3 reasons why this shouldnt be implemented:
1. People 'favoriting' their maps is not easy to develop, since it should remember, check availability, etc. A lot of things that eventually would be possible, but takes a lot of time. I'd rather see something more useful appear on the network than having developers putting their time into stuff like this.
2. Everyone has different favorite maps. this would make people join a lot of different maps. on a certain moment this could mean 6 different maps each have 3 players, and none of them could start. Besides gameplay experience, actually playing the game should be more important, hence this is a bad idea.
3. If people really care about which maps they play, they should return to the lobby and select one themselves. the feature was made so that people dont have to wait until the end of the game to enable auto-mode (idk if bedrock had it before, but java did). with the command you can enable the mode mid game, which is a plus.
TL;DR - due to some problems with developing, but mostly with gameplay experience, i absolutely think this is a fun idea, but it should not be implemented. Hope you understand! (

from me)