There are positives and negatives with all formats. So don’t really want to get into the nitty gritty.
My main concern is how would a switch in format effect the community as a whole?
Especially because the move to squad by NAH in 2017, has had (imo) a divisive legacy.
IIRC the format change was justified by an ambition to promote polo to corporations and sports broadcasters. However, we have seen little returns in that regard, and although there are some positives to squad it has also resulted in different regions playing different formats and a fair few teams / individuals losing an interest in the sport / competing.
I think therefore the question needs to be would moving to 4v4 be good for developing a competitive culture in bike polo [1]? And secondly would it help to promote the sport to the wider public [2]?
Regarding 1, I don’t think a move to 4v4 is likely to harm the competitive culture.
Primarily because I think that (for a variety of reasons) the competitive culture of polo has been struggling recently and now we have only a handful of established teams competing regularly.
However, it is possible that a fancy new format will galvanise teams to form and at the very least I hope that it would bridge the divide between the regions that favour squad and those that prefer 3v3.
Regarding 2, the old ideas of getting polo on TV seem antiquated to me now. I think that beyond the grass roots engagements with the public, the community should be focusing on content for social media and tournaments that can happen in high profile locations / events.
That all requires a lot of organisation beyond simply picking a new format…
That said, would 4v4 be compliant with promoting the sport? I think so!
With fewer teams than 3v3 tournaments it would be easier to host big events with one or two courts and with shorter games than squad tournaments the action will (imho) be more frenetic and exciting while also preventing stoppages in play.
In short, I think a move to 4v4 is unlikely to do any harm to the sport.
But I do think if we want to move to 4v4 in order to make substantial positive changes, then we have to ask ourselves if we are motivated do more than simply change the format?
Closing out my sermon here 
I’d like to end on this note (to self), that whatever happens in terms of format, organisation etc… let’s try and not get too partisan about it - at the end of the day we are a bunch of amateurs that like to ride around in circles and hit balls with sticks x
As Big Rik from the Rotten Apples said, polo’s all about the “Maximum Damage and Minimum Scandal”
From an organizational point of view, it also allows for more flexibility when someone is late or needs to work or whatever, which would not be the case in a “serious” tournament, right?