Since there is no multiplayer in PLA outside of trading and the satchel thing, are we going to ignore it for POTW? That would mean all of the new Evolutions/Forms along with Enamorus (& Samurott) would not be covered.
I would guess that Legends Arceus will be ignored for the time being due to the lack of multiplayer interaction. If it turns out we can transfer them to Home than to either BDSP/SwSh we may cover them, but not until then.
With absolutely no access to offensive Psychic type moves (Psychic Fangs), Glaceon is easily walled by fighting and poison types (Lucario, G-Max Machamp, Grapploct, Sirfetch’d, Toxicroak, etc).
I am confused on how Glaceon is "walled" by Poison and Fighting types. Neither of those types resist Ice. Fighting is Super Effective against Ice, but that is more worrying due to how common it is as a coverage move. Glaceon would rather prefer Ground coverage as it hits two types that resist it -Fire and Steel as well as hitting Rock types with their Super Effective STAB... Or Electric coverage due to Boltbeam still being a powerful coverage combination.
Glaceon has many problems -Mono Ice's horrible defensive profile plus the Eeveelution's propensity for having nothing in their offensive movesets bar STAB, Stored Power, Iron Tail and Shadow Ball. It might be forgiveable if the base 130 or base 110 went into Glaceon's Speed, but alas, we have yet another slow defensive Ice type. Base 130 Special Attack is amazing, especially with how potent Ice is as a STAB move, but 65 / 110 / 95 defenses aren't especially bulky. And yes, Slush Rush is a much better ability than Snow Cloak or Ice Body. The clerical abilities of Wish and Heal Bell would be nice... If Glaceon wasn't an Ice type and having such poor HP, ensuring it doesn't pass much healing with Wish and struggles to survive repeated uses of Heal Bell
Snow Warning users -both of Glaceon's abilities run off of Hail, and no miss Blizzard so having a partner that can seamlessly set it up for it makes Glaceon far more threatening. The users are rather interchangeable -you are going to be stacking Ice Weaknesses regardless.
Water types make decent partners for Glaceon, resisting Fire and Steel attacks, while also scaring off Rock types. Jellicent does this best, with a nifty Fighting immunity, access to Trick Room, pseudo bulk increase with Burns. Cramorant is another decent option -it resists Fighting in return for being weak to Rock, but has access to Defog to clear away pesky entry hazards.
Ground types also make for decent partners for Glaceon, able to strike at STAB users of 3 of its 4 weaknesses, but admittedly lack the necessary resistances baseline. Water Ground types are obviously excellent for this role, as is Golurk which does pack a Fighting Immunity. Claydol is more passive but can clear Stealth Rock away and ground types do like Glaceon's ability to pivot into Ice moves.
Checks and Counters
Look at the type chart. Look at Glaceon. Look at the type chart. Look back at Glaceon. Hug the Glaceon while weeping for its lot in life. Poor speed and a myriad of weaknesses makes Glaceon relatively easy to revenge kill and ensures it has a lot of problems hitting the field in the first place.
Entry hazards will wear down Glaceon quickly unless it is running Heavy Duty Boots.
Faster STAB users of its weaknesses like Hitmonlee, Lucario, Charizard, Salazzle, Kabutops, etc. can all come in and threaten out Glaceon, though to Glaceon's credit, it is hard for them to switch in safely without risking serious damage on their part.
Chansey and Blissey are hard counters to Glaceon, able to sponge its attacks all day.
Glaceon has no answers for Steel types, so any Steel type with sufficient Special Defense can reliably switch in and threaten Glaceon out. Silvally Steel, Cobalion, Bronzong, Assault Vest Copperajah all fit this role nicely.