I agree, which is why I went on to say that I think 5% is a more realistic target.
I also wouldn't discount the idea that some people are going to subscribe for political reasons, at least initially. HN seems to fairly consistently label Musk lately as "right -wing", but in truth he's become more of an "anti-left-wing" figure. By extension, I think that means that ~50% of the country is going to have a positive impression of his control of Twitter.
I've been watching right wing social media (forums, not Gab/Truth/MeWe/etc.), and they're relishing in the layoffs. That effect won't last long, but it'll likely have a measurable impact on subscriptions and a corresponding long tail.