Re: Old devices
Maybe it would be a good idea if they removed it's support in the ssh server code, and not (yet) in the client?
Or of course, replacng equipment wouldn't be needed: Just plug it instead to a small 2 port box with the other port instead going to the lan.
Run a hardened ssh server on the box, that relays to a less secure ssh connection privately to the device.
A small arm box/rouer could do that. The 50 quid edgerouter X, for example