Distracting myself by thinking of the current Eevee and eeveelution "leaks" (fan hopes at best) and want to throw my hat into the ring.
Eevee and the current eeveelutions account for 9 of the 18 current pokemon types.
What if the Pokemon Company decide to go the route of the Galarian Legendary Birds and remake the eevee line for the remaining types not represented?
Instead of releasing new eeveelutions, they introduce a new Eevee form (named like Galarian Eevee but for the new region instead) and all the current eeveelutions get new forms that are the missing types. They'd use the same names similar to how the Galarian Bird names were the same with pokedex entries explaining why Articuno was a psychic type now, etc.
How I think the new typing could work:
Alt Eevee- Ghost *counter to normal type Eevee
Alt Vaporeon- Poison *Toxic vapors
Alt Jolteon- Fighting *Quick on its feet and ready to "jolt" into action (similar to Galarian Zapdos)
Alt Flareon- Ground *Digs so deep into the ground that magma pools form when it resurfaces (similar to Primal Groudon)
Alt Espeon- Flying *Though it does not have wings, people speculate it flys through the air with psychic power
Alt Umbreon- Dragon *Associated with scary nighttime stories told to children, known to lurk in the shadows and avoid people
Alt Leafeon- Bug *Found in forests resembling leaves as a form of camouflage
Alt Glaceon- Rock *First discovered frozen in a Glacier (similar to Mamoswine's pokedex entry), believed to be an ancient eeveelution
Alt Sylveon- Steel *Silvery coat
I feel this would be an easy way for Pokemon to follow their current trend or "reimagining" species from previous generations.
Feel free to chime in with your own thoughts!
