It's a gimmicky thing to give other Pokemon the signature moves of the starters.
All of the Kalos ones lost that status(except Greninja's Mat Block) in ORAS where Cacturne got Spiky Shield alongside the other two moveset additions you mentioned.
Also, Razor Shell was given to Cloyster and Coil to Eelektross(though this was from the beginning of Gen V), Emboar's Heat Crash remained exclusive to it.
Hitmonlee got Blaziken's Blaze Kick, a bunch of Pokemon got Sceptile's Leaf Blade and Swampert's Muddy Water in Gen IV.
Wonder who they'll give the Alolan moves to, Darkest Lariat is something any physical Dark type wants and ditto for Spirit Shackle on Ghost Pokemon(though it works on anyone simply due to the coverage it provides). Sparkling Aria could be good in a Pokemon who "should learn Surf but doesn't"