It's nearly free if they simply changed their archiving process from deleted to read-only with a giant red banner warning at the top. Both expend the same amount of effort to do.
Heck you could even scrape + convert to static HTML like what they did with the original Processing forums. Which is run by volunteers.
I totally get your point and am pro non-deletion, but it really is way less work to just delete it all.
It's probably a month of work for anyone competent to produce a static version of ALL of the posts.
But f00kin'AYE on wget.
I can't say for certain (please pard0n) but if there was anyway to (ya, right) find we'd learn way back when 'AutoCad' was originaly built (and for) UNIX.
Because LISP (Lost In Stupid Parentheses) was an emacs dealio, Richard Stahlman stuff but I suspect even before Torvalds built Linux...
When 8086/88 machines went viral there was a (hardware) limit <640K (kb) RAM.
To escape this we used 'PharLap' to make a 16mb (megabytes) Ramdisk look like "REAL" to Autocad...
It'd be amusing to know how the UNIX app was ported to 8086/88 (before 'Windows' 3)