Ok, clear. If there would be no other solution (because I don't know if upgrading my vB3.8 board to vB5 first and
then migrate to XF2 -to save the vBlogs as threads) has any negative consequences) I would choose the path you describe. But obviously I would prefer an officially supported solution, so I am really pleased to read what Kier writes:
This would be great, thank you for considering this

. I hope it is doable.
For a long time (for several reasons) I held back migration my vB platform to Xenforo. And the omission of Blog functionality in Xenforo 1 was one of these reasons. I am now at a stage where I need to simply bite the bullet and migrate straight to Xenforo 2. By now... the
countless pros of migrating vB 3.8 to the new XF 2 outweigh the con of loosing our Blog
functionality. But if Xenforo could offer us a way to save the contents of these blogs inside threads, then the contents are at least still accessible (publicly/visibly) and do not get permanently lost. This would definitely be a great solution for the situation I (and I assume more people) am in.