Well... I think this would be a start for certain units/armies.
I have no clue why I should even bring a unit of Bloodletters in a daemon army (oh wait; I know... to man a Quad gun). If I deepstrike them and they stand there waiting for a turn they're not going to do a lot. And walking them over from my deploymentzone isn't helping a lot either.
Granted, a unit of powersword wielding models for about half what a full marine squad costs that will most likely chop up a full squad in 1 go sounds a bit OP I guess. But right now a unit like that doesn't do a lot at all.
And yes, that's Assaulting from Deep strike...
Similarly Genestealers from reserve... an outflanking specialized CC unit does what? Most likely die, cause it can't assault. Outflanking stuff like that should be fast and dangerous. I thought that was the general idea.
Coming from reserve now feels more like the only ones actually having a benefit are the ones with at least a 3+ save, just in order to prevent them from not getting shot up before they do a thing.