Legacy System Extension warning on 15.4 Beta 2

Saw the same alerts with Crowdstrike and Dropbox. Crowdstrike actually put out a tech alert indicting they were working on a fix, but my guess it won't be available until after 10.15.4 drops.

This article sheds some light on ktext changes.
https://www.sentinelone.com/blog/7-big-security-surprises-coming-to-macos-10-15-catalina/

Starting with macOS 10.15 Catalina, security vendors are being asked to move to the new EndpointSecurity and SystemExtensions frameworks and away from kernel extensions, which are now formally deprecated. That means developers will still be able to use kexts in 10.15, but new technologies are being provided to encourage the transition to a kextless future, most likely starting in 10.16.

However, that message sounds like more changed API's (not ktext) that Microsoft has to update.
Which.. may be fun with what other 3rd party venders are doing as well potentially.

This is a regression in beta 2. The proper behavior as we saw in beta 1 and expect to see in beta 3 and further will be that any KEXT that is approved via Configuration Profile will see these messages surpassed.