My question would be how they treat companion multiclassing - unlike BG1&2, when multiclassing was picked during character creation, in 5e multiclassing happens on a level up.
It’s a good question. It certainly seems possible that for some characters, particularly non-origins ones, they might be at higher levels when we meet them so may come multi-classed already. Personally I’d be fine with that and wouldn’t necessarily want to tweak it, but I can understand that others want more flexibility. Though even if companions do come with a few levels already, we might get the ability to respec. Could go a variety of ways!