We have seen how bad backfill can be, loading into a game just to have it end 30s later is a major bummer so we are looking at ways we can make this system more efficient. Most likely we will set a point during each Warzone when it will no longer backfill, based on time remaining and/or a score differential between the teams.
Backfill won't be eliminated outright because it does serve a valuable purpose, we just want to make it better.
In addition, we also looking into (but no promises) the idea that we grant a medal for backfilling into a game that is in progress, to help make sure those backfillers don't miss out on rewards by not having enough time to get a medal on their own.
That last part shows that this was not just a random post to please the masses, but you actually have read some suggestions.