Thanks @IvaRo - Pulse 3 is quite old now and no longer supported. Any Pulse 3 users will be happy to upgrade to Pulse 5 as it has the best features of both 3 + 4 (and more!)
Those pages you mentioned will remain in tact:
The forum keeps its own archive; addons will work for both 4+5, help is also something which is growing.
That said, of course there'll be more resources directed at Pulse 5 overtime and in say 12 months, most of the tutorials, docs and other things will be focused on Pulse 5 so that should be enough time for people to adjust, upgrade and get used to the new stuff