Incorrect - though they had a ‘directory’ of plugins they DID support - a whole forum section, and, even a web based plug-in was made to allow for, unsupported plug-ins.
I still heavily use 2-3 non agent plug-ins that I know will be removed at some time.
I probably use those more than actually viewing my library media.
I find that they’re removing it extremely upsetting and frustrating.
See the announcement link blog and FAQ forum post.