The first 4 Allied races are not BFA content. They came in legion and you needed and still need legion reputations. They only wanted you to preorder BFA because they knew it would suck because they didnt put any effort in it and you could see it even back in the alpha.
Back to the original topic: Of course they will spread out any given content as much as they can to keep people subscribed. Also they will put out the Aliied races between the raids to keep all them casuals happy. That is not even a secret.
Its not about good gameplay or content anymore. Its just about milking every last customer as much and as long as they can at this time. If 8.2 sucks as much as 8.1 WoW ist dead.