If you have made yourself Large, then yes, Small creatures can move through your space because you are 2 sizes larger than them (and you can move through theirs). This is how it has worked since 2014.
MOVING AROUND OTHER CREATURES (UA2022-Expert-Classes)
During your Move, you can pass through the
space of an ally, an Incapacitated creature, a Tiny
creature, or a creature who is two Sizes larger or
smaller than you.
Another creature’s space is Difficult Terrain
for you, unless that creature is Tiny.
You can’t willingly end your Move in a space
occupied by another creature.
The change now is that they extended it to cover Incapacitated creatures (and Tiny critters regardless of your relative size).
No, the new grappling rules are completely messed up, because any goblin can grab a hold of the Barbarian and drag them off, when previously his higher Str + Athletics .