Hi Denis,
Yes it has been removed.
What you've linked is the "official and documented way" of getting this info, yes. If you only need to have access to layer IDs, maybe the official endpoint is enough.
If you want more, you might find the same information at the endpoint we use on the frontend, although maybe sorted a bit differently (no multiple arrays, now everything is based on flag, such as "chargeable" or "searchable").
It's still undocumented territory, as it is only used by our frontend app (not something we officially publish, but it's there). So we might change things here without noticing you. But as the frontend is using it, it's not bound to disappear anytime soon.
Cheers,
Pascal