Just tested it with my morphs var file and mine worked, all I did is ticked the preload setting in vam and did hard reset and all the morphs from the var were visible.I packaged them through VaM and my meta looked just like that, except preload is true. Like, before packing. I check how many female and male pages I have. Pack, remove the legacy out of VaM, re-open and they are not populating the tabs, even the few that were set to preload, while the biggest package is set to preload in the meta, in VaM it unchecks itself. Checking it and rescanning (which forces vam to discover newly added vars) and nothing.
Maybe you have too much morphs in your var file that is just too much for vam to handle...
Have you tried the cleanup guide that I posted? you should use it regardless just to clean all the duplicates.
I can upload my morphs var file if you like, I belive it have everything that you need.