Hey Fabian,
Great questions! Let me see if I can give you some good answers 
Currently, everything we have of note today about support of the CoLab items is on the topic below.
There are currently no explicit requirements at the time of this writing beyond what you inferred: partners are encouraged to support the integration and accept contributions from your peers. If we see integrations being unmaintained, we may tag them as unmaintained and look for a new owner/maintainer in the community.
It is possible we add more requirements one day, but we didn’t want to have too much of a barrier for people to contribute on either end, to start. Are there any requirements you think you might want to see us add?
That is entirely up to you and any agreements you have in place with your employer. Good question!