Wow what's with the reddit hate on here? I honestly find reddit better than the official forums. Just don't take everything on reddit as fact the same way you would on the official forums if someone made a thread saying something that isn't confirmed.
Also I will be honest with you the sub numbers are not as high as you think. I would say its in the 400k-500k range and that's being generous. It will increase with the expansion but drop again quite quickly. It's not really being doomsayers but looking at the game realistically based on some data people have gathered. The data isn't from SE so you can't say its official but its the closest thing to active players of some form pulling data from the lodestone.
If you don't see a source on the post then don't believe it straight away. Most of the time people would put a source with it to prove what they say.
Also generally you get information faster due to people looking at the JP forums quite often ;D