I was hoping to see a couple use Catalyst[1] but checked a couple & appears not so.
Also it'd be lovely for those who are going in on Catalyst to have some well written robust components to either imitate or extend. And if multiple components are leveraging the shared Catalyst library, the marginal size of using a new component ought be significantly less.
Even without, thanks! Leaving Catalyst version available does seem like an excellent learning opportunity for all, & have some great technical upsides, but it's great that these components are available.