Removal of availablePlugins breaks addons

[rykov]

A number of older addons break with ember-cli-preprocess-registry versions 4.0+ with the following error:

Cannot read properties of undefined (reading '...')

We've traced it down to the removal of availablePlugins from registry.

We've seen this problem with the following plugins:

• ember-basic-dropdown
• ember-power-select
• ember-side-menu
• and there seem to be more...

Is this an intended breaking change?

[lougreenwood]

Any news on this?