Considering 15.2 is currently in Alpha,
I don't know what should be expected, only that things are so early one should expect a ton of things to be broken and will need to be fixed. And, for that reason it's really too early but the most curious to install 15.2 at the moment.

This is a short summary of current status of the very latest 15.2 configured for an original LXQt DE running on the very latest VBox installed from Oracle (6.1.2).

Noticed the extraordinarily large download (about 6GB total) which wasn't too surprising since until officially released I'd expect that there's plenty of tracking code everywhere that will be removed eventually.
Kernel 5.3 which is both surprising and disappointing. Had hoped to see at least something on par with TW. No real importance now though, of course. I expect that by the time 15.2 ships it will have at least 5.6 and that will likely involve lots of work modifying numerous applications.

One of the first things I noticed is that 15.2 seems to be continuing the broken install for DE other than the standard ones offered in "System Roles" -- Too bad, since it was removed IIRC literally a week before the 15.0 launch for unknown reasons, it's never been fixed so a long explanation has to be provided every time someone wants to install something other than Gnome or KDE as the only DE... which is often and growing as other distros eliminate their support for more than one or two DE and come to openSUSE for their favorite DE.

Currently, looks like not too much has been done to integrate LXQt, the usual apps display as menu options but the usual problems with every release are there... The background is default which usually means the path to where the openSUSE recommended images is likely incorrect.

It looks like the base install upon detecting Virtualbox might have tried to install the VBox HostOS (main) app instead of Guest packages.
So, my first test was to go ahead and install the VBox Guest packages, and there are a lot of them now (I think there were more than 6?). Despite being the correct version (6.1.2), they're currently broken. No change.
After uninstalling the openSUSE virtualbox packages (all of them)
I installed Guest Additions using the ISO.
Found that the compile dependencies were already installed (Is this intentional? I would have assumed those would have been removed even for the Alpha)
Successfully built the kernel modules, and install went fine.
Found that the background was now completely black, but otherwise all the Guest Additions functionality I tested was working.

IMO 15.2 Alpha is only for the curious at this point,
There's plenty of work that has to be done before Users can experience something close to more usable than broken.
That is, unless Developers for specific areas have worked on something and put out a request for Users to try that out...