diff --git a/components/autocomplete/completer-compat.js b/components/autocomplete/completer-compat.js
deleted file mode 100644
index aedffd61b16d9d..00000000000000
--- a/components/autocomplete/completer-compat.js
+++ /dev/null
@@ -1,61 +0,0 @@
-/**
- * This mod
- */
-
-/**
- * WordPress dependencies.
- */
-import { deprecated } from '@wordpress/utils';
-
-const generateCompleterName = ( () => {
-	let count = 0;
-	return () => `backcompat-completer-${ count++ }`;
-} )();
-
-export function isDeprecatedCompleter( completer ) {
-	return 'onSelect' in completer;
-}
-
-export function toCompatibleCompleter( deprecatedCompleter ) {
-	deprecated( 'Original autocompleter interface in wp.components.Autocomplete', {
-		version: '2.8',
-		alternative: 'latest autocompleter interface',
-		plugin: 'Gutenberg',
-		link: 'https://github.com/WordPress/gutenberg/blob/master/components/autocomplete/README.md',
-	} );
-
-	const optionalProperties = [ 'className', 'allowNode', 'allowContext' ]
-		.filter( ( key ) => key in deprecatedCompleter )
-		.reduce( ( properties, key ) => {
-			return {
-				...properties,
-				[ key ]: deprecatedCompleter[ key ],
-			};
-		}, {} );
-
-	return {
-		name: generateCompleterName(),
-		triggerPrefix: deprecatedCompleter.triggerPrefix,
-
-		options() {
-			return deprecatedCompleter.getOptions();
-		},
-
-		getOptionLabel( option ) {
-			return option.label;
-		},
-
-		getOptionKeywords( option ) {
-			return option.keywords;
-		},
-
-		getOptionCompletion() {
-			return {
-				action: 'backcompat',
-				value: deprecatedCompleter.onSelect.bind( deprecatedCompleter ),
-			};
-		},
-
-		...optionalProperties,
-	};
-}
diff --git a/components/autocomplete/index.js b/components/autocomplete/index.js
index 514c0e55bf4566..b08b10899105b3 100644
--- a/components/autocomplete/index.js
+++ b/components/autocomplete/index.js
@@ -15,7 +15,6 @@ import { __, _n, sprintf } from '@wordpress/i18n';
  * Internal dependencies
  */
 import './style.scss';
-import { isDeprecatedCompleter, toCompatibleCompleter } from './completer-compat';
 import withFocusOutside from '../higher-order/with-focus-outside';
 import Button from '../button';
 import Popover from '../popover';
@@ -207,36 +206,6 @@ export class Autocomplete extends Component {
 		};
 	}
 
-	/*
-	 * NOTE: This is necessary for backwards compatibility with the
-	 * previous completer interface. Once we no longer support the
-	 * old interface, we should be able to use the `completers` prop
-	 * directly.
-	 */
-	static getDerivedStateFromProps( nextProps, prevState ) {
-		const { completers: nextCompleters } = nextProps;
-		const { lastAppliedCompleters } = prevState;
-
-		if ( nextCompleters !== lastAppliedCompleters ) {
-			let completers = nextCompleters;
-
-			if ( completers.some( isDeprecatedCompleter ) ) {
-				completers = completers.map( ( completer ) => {
-					return isDeprecatedCompleter( completer ) ?
-						toCompatibleCompleter( completer ) :
-						completer;
-				} );
-			}
-
-			return {
-				completers,
-				lastAppliedCompleters: nextCompleters,
-			};
-		}
-
-		return null;
-	}
-
 	constructor() {
 		super( ...arguments );
 
@@ -466,7 +435,8 @@ export class Autocomplete extends Component {
 	}
 
 	search( event ) {
-		const { completers, open: wasOpen, suppress: wasSuppress, query: wasQuery } = this.state;
+		const { completers } = this.props;
+		const { open: wasOpen, suppress: wasSuppress, query: wasQuery } = this.state;
 		const container = event.target;
 
 		// ensure that the cursor location is unambiguous
diff --git a/editor/store/selectors.js b/editor/store/selectors.js
index 5c7978d7459972..7e2ad7981747f8 100644
--- a/editor/store/selectors.js
+++ b/editor/store/selectors.js
@@ -26,7 +26,6 @@ import { serialize, getBlockType, getBlockTypes } from '@wordpress/blocks';
 import { __ } from '@wordpress/i18n';
 import { addQueryArgs } from '@wordpress/url';
 import { moment } from '@wordpress/date';
-import { deprecated } from '@wordpress/utils';
 
 /***
  * Module constants
@@ -1294,15 +1293,6 @@ function buildInserterItemFromSharedBlock( state, allowedBlockTypes, sharedBlock
  * @return {Editor.InserterItem[]} Items that appear in inserter.
  */
 export function getInserterItems( state, allowedBlockTypes ) {
-	if ( allowedBlockTypes === undefined ) {
-		allowedBlockTypes = true;
-		deprecated( 'getInserterItems with no allowedBlockTypes argument', {
-			version: '2.8',
-			alternative: 'getInserterItems with an explcit allowedBlockTypes argument',
-			plugin: 'Gutenberg',
-		} );
-	}
-
 	if ( ! allowedBlockTypes ) {
 		return [];
 	}
@@ -1364,15 +1354,6 @@ function getItemsFromInserts( state, inserts, allowedBlockTypes, maximum = MAX_R
  * @return {Editor.InserterItem[]} Items that appear in the 'Recent' tab.
  */
 export function getFrecentInserterItems( state, allowedBlockTypes, maximum = MAX_RECENT_BLOCKS ) {
-	if ( allowedBlockTypes === undefined ) {
-		allowedBlockTypes = true;
-		deprecated( 'getFrecentInserterItems with no allowedBlockTypes argument', {
-			version: '2.8',
-			alternative: 'getFrecentInserterItems with an explcit allowedBlockTypes argument',
-			plugin: 'Gutenberg',
-		} );
-	}
-
 	const calculateFrecency = ( time, count ) => {
 		if ( ! time ) {
 			return count;