Like much of the English language… it is somewhat ambiguous.
If we let you_will_move_on be a boolean value then,
we’ll reach out via email to let you know if you’ll move onto the next stage of the application process
Could be interpreted as,
if you_will_move_on:
reach_out()
or,
reach_out(you_will_move_on)
The most “correct” interpretation is the first, but many people will read it as the second, partly because they are adding what they perceive as an implicit term,
we’ll reach out via email to let you know if you’ll move onto the next stage of the application process or not
The “or not” isn’t there, but in common, conversational, English it’s often implied. “I’ll let you know if I can make it to your party (or not),” etc.
I agree it would be nice if they had sent out messages saying “Than you for applying, unfortunately…” But, they did not.