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.
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.