They just released native support for those:

Controller script added for Novation Launchpad Pro MK3 Controller script added for Novation Launchpad X (via reassigning the Rec Button) Controller script added for Novation Launchpad Mini MK3 (via the special 4th row buttons) Controller script added for Akai APC Mini MK2 Controller script added for Akai APC Key25 MK2 Controller script updated for Novation Launchpad Pro (MK1)

Wouldn't the onus be on the controller manufacturers to ensure compatibility?

Push is made by Ableton. I am not sure they are willing to help a company build by some of their ex developer who left them to build a new DAW with possibly stolen code and at least many ideas that were discussed internally.

Despite the headquarters proximity, I think they are not the best friends.

Not so sure about the "stolen" part. Bitwig code has a completely different code base (Java backend with UI written using Juce), and the sentiment at the time was that a few devs were frustrated by Ableton management rejecting several proposals that ultimately were implemented in Bitwig.

Also the multitake tracks UI that was implemented in Live 11 is basically a (slightly improved) copy of the same feature on Bitwig.

The stolen part mostly relates around the sales and distribution network, less around the code. Basically the sales equivalent of IP theft, and a really huge douche move by their CEO. Makes him very unsympathetic to me. Not as bad as Behringer but close.

I think it's the other way around, the Bitwig UI is what appears to be coded in Java.

Bitwig is extremely niche. Waiting around for controller manufacturers to implement isn't going to happen.