It will come, but until it is ready it is tricky to estimate how long it will take. This partly depends on how quickly Microsoft makes changes to 2019, and how big those changes are.
We got access to it at the same time as all other users. We are testing to see what works and what is broken. We know right now that VA Step Filter does not work with the new external symbol debugging feature (which is enabled by default).
Preliminary/preview support for vs2019 is case=132624. Broken Step Filter is case=132670. Yellow warning bar re: extension at risk of not functioning in future VS update is case=112957.
I extracted the vsix and tweaked the supported version range to check myself :-)
Was installed but could not enable VAX. Almost all VAX menus were disabled - so it seems you need to tweak a bit more. Would love to beta test the current state you have.
I think the yellow bar is coming up as the extensions are supposed to implement async load to keep supported in the next update to VS like 16.1
We're still encountering issues with our automated testing. Once we have some confidence that most things are working we'll release an update with preliminary support.
Yes, the yellow bar is due to async load. VA has a number of Packages that have been ported to AsyncPackage over the last year, but there is one remaining that we should wrap up during the Preview 1 timeframe.
Build 2302 has preliminary support for VS2019 Preview 1. We have continued to experience much difficulty with our automated testing.
Known issues at this time: VA Step Filter does not work when `Load debug symbols in external process is enabled` (new VS feature, enabled by default); yellow bar notification regarding extension at risk of not functioning in a future VS update; changes expected in Preview 2 will almost certainly require another update of VA (build 2302 is unlikely to integrate properly with VC++ in Preview 2); preview instability has greatly impacted our ability to test VA in it.