We're going with Swarm exactly because of the reasons you've listed. The EE part is a bit flaky sometimes (I'm looking at you, UCP), but Swarm is brilliant.
I don't think that you need to be afraid and migrate just because of that. Swarm is not a service, so if they stopped developing it then you'd have plenty of time figuring out how to move away because your Swarm clusters would not stop working.
Also, there are very large Swarm installations in production at large companies, so I'd be surprised if Docker cancelled the product (which is their flagship).
I would love it (and pay for it) if Swarm says that it is a opinionated distro (ingress/overlay) + management layer on top of k8s.
The silence is deafening and not nice.