I imagine it was a mistake, but it could have been a set-up to stick a toe in the water. If it was a mistake, somebody is really getting familiar with the top of her/his shows at the moment. Ah, well, mistakes happen.
It's no matter, it's going to be what it's going to be. Knowing about it now or knowing about it in July really makes no difference to me. I think IB is making some pretty serious mistakes with these new policies (as one person asked, what is next, PPV vB.org?), but they own the business and not me.
I imagine my sites will remain 3.X sites, unless the 4.0 upgrade price is ~extremely~ cheap. I suspect it won't be, which is why they have likely dropped the annual renewals.