Player counts are expected to plummet like any other game. I'd guess anywhere between 85-95% of players who try MP will quit within the next month or two, before stabilizing for the long term audience. The stabilization count is key, and it's still much too early to start judging what it will be.
For example of a hyped game like BL, take a look at the general interest for Apex:
Obviously, the games are very different, but this graph should give a basic representation of what will happen in BL. Currently, BL is still at the peak and Google hasn't even finished tracking the height yet.
That said, starting off SP will full support, constant attention, constant patches, and full devition is going to HARD push the 2-2.5% ratio of SP:MP we saw in Warband. Maybe lower. If MP received the same support, attention to balance, and constant patches in-line with the best community feedback, MP would have more players and the ratio would be much different.
Like, what's the
worst that could happen if a patch made control for attacks and blocks more responsive. Would new players get bullied by veterans? Because that's already happening and will continue to happen and will
always happen, unless you made combat governed by RNG.
Multiplayer is difficult for new players to enter for a variety of reasons. People have the following options:
Siege: Good, but has performance issues and a lack of face value "new experiences" for new players unless you start working out the details of siege engines or general flow of maps. Also a bit unbalanced.
Captain: Not true PvP, but seems reasonably popular and fun. Average game quality is hilariously low
TDM: Chaotic mess where you're spawnkilled from behind unless you play as cav. Not very appealing for newcomers
Skirmish: Hope you're ready to be rolled by stacks of experienced players every other game. Average game quality is either one-sided stomps or reasonable stack v stack.
(Note: A major caveat is that I haven't played siege very much because it's too laggy for me to fight good players well, and just farming new players gets boring pretty quick. So maybe siege is a haven for new players.)
There's four times the interest for Bannerlord Multiplayer compared to the height of Warband Multiplayer, according to Google Trends.
Yet from my experience on NA, it's mostly Beta and some Warband veterans running around while new players quit MP halfway through a round after getting trashed by stacks. It's hard to know the numbers.
While it's expected that a huge portion of these players will immediately quit MP, I can't help but feel that number is much higher than it needs to be.