JEB
Legend
Eh. We don't have nearly enough information yet to make that assumption.There is just no way that WotC is going to present a major setting (as opposed to a sort of one book once off like Theros) with any support that doesn't include all the main races and classes. Gone are the days where picking up a given setting meant that you had to put 3/4 of your gaming collection on the shelf because you couldn't use it in that setting.
Like it or not, moving forward, settings are going to include all the major races, certainly all the PHB races, in some form or other - like replacing Dray with Dragonborn a la 4e Dark Sun.
Excluding SCAG (the Realms is default 5E, no matter what they say) and Ravenloft (expanding on a Realms-compatible 5E adventure), we have two one-off setting books which use all the core races (Eberron and Wildemount) and two one-off setting books that explicitly do not (Ravnica and Theros). Note also that neither Eberron nor Wildemount are settings that would be expected to limit race options; it would have been surprising if they had, in fact. One might also wonder if Ravnica and Theros were testing the response to a limited race selection. (I don't recall seeing anyone upset by it, but it may have happened.)
Most notably, none of these are settings that historically had limited race options, but are now open to all the 5E things. That situation simply hasn't happened yet. Until it does, we can only guess, but we can't assume anything. However, I'm pretty sure we'll find out the answer next year...