It would be very interesting to know Monzo’s thoughts on this, but I doubt we’ll get them.
My reckoning is that Plus will tempt some current Monzo users to upgrade, but I also think that Monzo’s basic account will suffer and fewer people will switch from other banks to monzo.
In fact, we already know that Monzo’s basic account is suffering… just look at the (now locked thread) about monzo stagnating. It turns out the development has been just as active as ever, but it’s all paywalled. And I very much suspect that features we were teased with (eg credit scores, seeing credit cards in monzo) were originally intended to be released to everyone, but have since been paywalled.
Disappointed? Yes. Paywalling features was pretty much the one thing that almost everyone said they didn’t want to see in new Plus.
There’s a lot of excitement here about new Plus but the wider feedback in other places (eg Reddit) is much less favourable.
A wise commercial decision? I don’t think so. Everything in Plus is too easy to copy, and too easy for other providers to undercut.