The amount of running around in circles trying to find a perpetual licence version of LR6 leads me to believe that Adobe has no real interest in continuing with this format.
At every turn it's, Creative Cloud this, Creative Cloud that.
Clicking my PL LR5's "Check for updates" tells that an update is available, but clicking "Download" takes me to Creative Cloud, nowhere was there a link to a PL download.
Through a lot of clicking, with no help or direction on Adobe's site, I did eventually find a PL download link tucked away - I wouldn't like to attempt to find it again.
Unfortunately, along the way it seems that I clicked on one or two wrong links, Adobe now thinks that I'm interested in CC and is sending me "Welcome to Creative Cloud" emails.
Got a feeling this will be my last LR purchase.
No, thankfully the perpetual version is still available, as you've already guessed, but Adobe certainly make it difficult for any but the most determined.
You should be able to find it by going to "Products" at the bottom of the Home page and scrolling down to Lr in the presented list.