I don't see any windfoil boards on their website.

Yes, Slingshot has indeed exited the windsurf foiling market. I had the same question myself, so last year I asked, and here's the response I received:

I just got one of the last 2 Wizard V4 90L in the US. My son knew I was interasted in a 90L. He called Slingshot and they said there were none in the US, and they weren't going to import anymore.
They called him 2 days later and said the "found' 2 in inventory. So glad I got one. Should have done it a year ago. I've retired the 114 after a billion hours

Nice! That surprised me that they had a couple to offer also free shipping.