Collaring is absolutely about commitment to each other, it isn't just about the submissive or bottom wearing a piece of leather with a buckle. This is about Trust, not just the Trust that the Top or Dominant will try to never go against the bottom / submissive's Hard Limits. Its also about the submissive or bottom to be trusted to be Open and Honest with their Dominant partner and with themselves!
A BDSM Collar is also NOT a dog Collar!
In the past, a Leather Top would actually create with their own hands the Collar that the submissive or bottom would either wear for their term as a submissive to that Dominant / Top. Rather than these days, just pick one off the shelf...
BDSM Collars usually have Collaring ceremonies, to commemorate the Collaring time, the Commitment. As also there are many different types of BDSM Collars, Commitment Collars, Protection Collars, Play Collars, Posture Collars,
There are Play Collars which are still NOT Velcro Collars or the "Weekend" Collar... Being able to remove the Collar for work or bio-family life. As it is close to impossible to actually live the BDSM Lifestyle 24/7 365.
If the bottom or submissive no longer wishes to be in service or even associated with the Top / Dominant, they do have the right to RETURN the collar to the original Top or Dominant with the removal request! Not try to flushing the rejected Collar, only having to dispose of it later...
Personally, if ever presented as such a Request Of Removal, I will accept the request without hesitation! Do not wish them to be around me if they do not want to be around me... Always reminding those where the exits are at all times!
Sure they can tell me their reasoning, I will listen, then I move on.