Why would you expect to ever hear about it even if it was happening? The result would be a company failing to build a working product due to struggling with hir

Why would you expect to ever hear about it even if it was happening? The result would be a company failing to build a working product due to struggling with hiring, which is an incredibly normal thing. Interviewing with a company, deciding you don't want to work on the thing they're building and then later hearing that they failed isn't exactly unusual, but no one involved is going to know that it failed specifically because developers were morally opposed to it rather than some other reason.