Lish shouldn't be impacted by your changes. Lish uses console access (over a virtual console serial interface), so won't be impacted by any restrictions you put on ssh sessions. You do use ssh to reach the Lish server itself (and can separately install keys in the manager and disable password support for the Lish connection), but the link from Lish to your Linode does not use ssh. It works even if you completely shut down networking on your Linode.
– David
