Only big changes and content drops through season updates cause players to return. Minor changes don't bring players back, however without them, players quickly depart again.
Unless people enjoy paying $50-100 for AAA games to sit in empty matchmaking lobbies, of course.
Making servers persistent may be a little more time consuming, but the server browser list should actually be very easy - because it is only a UI.
1) Link server / experience ID's to a UI slot; gathering the player-count and map data from that ID is already functional (it displays & names the map we're about to play on, and it knows the player-count when referencing whether to join an existing match or start a new lobby)
2) Connect the "JOIN" button - other functionally exists as-is through MM. Can implement it as if it queues MM, but insert that server's ID in the joining field as a "found match".
3) Queues - they already exist when you join off others, so nothing needs reprogramming there either.
Nothing they haven't done multiple times prior though. MM is essentially a server browser without the UI, it goes through the options and picks for us.
I truly believe they can easily implement this for substantial player benefit and enjoyment, so I'll keep pushing 😉. Even if we're back to lobby after each round, at least we see what is going on and choose things ourselves.