Again I ask, where's the contrast: why do they want goliaths and orcs in the PHB? I contend it has far more to do with CR than anything else.
As mentioned above, what about kobolds and goblins? Very popular choices eternally relegated to supplements.
I mean you cannot have all the options, and we already have 3 small options right? I'd argue PF Goblins are far more (PF1 especially) interesting, than Wizards Goblins, so they can just keep it to Dwarf, Halfling, Gnome.
As far as the 'we are not Large, but bigger than Medium somehow' we only had the Dragonborn*, and Half-Orc, with Half-X perhaps short on time.
So, if we have 3 small, lets have 3 'not Large'-large ones? Dragonborn*, Goliath, Orc?