I am not sure what to make of it. Its almost like they are saying, don't be a jerk about it and if it makes sense that one landraider has a rule the others should. Personally, this is how I would deal with it, but unfortunately, not everyone is that open minded, especially at tournaments. In these cases I guess its up to tournament organizers to make rulings on these before they start. Hopefully, down the line they will get a chance to go through the rules and codices and find all the differences between equipment rules and FAQ them. But right now at least they addressed it.
Ten bucks says they're both playtesting the older codecies with the new equipment profiles, as well as sitting down with a spreadsheet and trying to decide if it's financially sound to give the updates.
Now, you say, of course it'd be financially sound to give the other Chapters the updated rules-- how could that hurt? Well, the short answer is that if you Black Templar, Blood Angel, and Dark Angel players out there suddenly had access to the stuff you ought to out of the new Codex, then why buy the stuff you need to reconfigure your army to act as a Codex: Space Marines army? I bet you anything they wait a few months, let everyone get some units so they can play divergent Chapters with the Codex rules, and then come out with the FAQ to give the other codecies the new stuff. It's ultimately a question of sales, and it really seems to me like it'd hurt their sales on the Space Marine releases, as utterly crazy as it sounds, if they release the FAQs now.
As a side note, I do like the fact that they're telling everyone to just sort of deal with it as you see fit. I hate rules lawyering, and I hate the stubbornness attached to it that detracts from the fluff of the game. Codex A says this, but Codex B makes more sense and has the rules written there. Codex A and Codex B don't functionally differ in any meaningful way as far as actual units go, so for the love of the Emperor, just go with what makes you happy. It's YOUR game, after all-- you're the one playing, not some jerk behind the counter at the GW store.