This is not a matter of going public, but I note that when MS bought Github, there was a lot of concern over whether that would degrade the service's customer-friendliness. So far, that doesn't seem to have happened? You don't need a MS365 identity to set up a github account, for example.

Also not going public, but Fastmail was bought by Opera in 2009 I think but then bought themselves back out again, and they've continued to offer excellent customer service (including yubikey support of which they were an early adopter) all the time.

So I'd say there's precedent for companies staying customer-focused under capitalism if the stars align: it has to be a place where (1) staying customer-focused is a clear net positive for the domain they're working in, even from a revenue perspective and (2) the people running the company understand this.

I imagine this is much more the case for companies where the customers are specialists / power users (think: developers) or other businesses, rather than the general public. I hope that means yubico of all places is lower risk. Although I consider them one of the best if not the best in the market, were they to go under, there are alternatives (google's own titan keys are ok replacements for the end user, though obviously they don't have the yubico back-end infrastructure). FIDO/U2F etc. are standards and come with certifications, so I'd hope there's only limited room for maneuvre for any new yubico owners to mess up, and a sufficient threat of losing their business that they are not incentivised to try anything too shady.