Yes, support will continue for Visual Studio. Several changes are required for Visual Studio 2019, they are moving away from the old way of how we detected older versions and product paths. They have tools and API's for the new way going forward, but the changes are far too much for a hotfix or even a point release. SlickEdit version 24 will have this included later this year, and will go through the usual beta test cycle.
We may need to issue a v23 hotfix to mute the warning specifically for Visual Studio 2019 for the early adopters, but would still require manual setup of environment settings for builds and manual tagging of the 2019 standard libraries.