An important philosophical quandry

What about all the pokemon that just straight up don't evolve? Are they immortal?

Look, her second favorite pokemon is an Orthworm named Gummy and he's at least more immortal than a very cute grasscat was.

What about Tandemaus, whos evolution (Maushold) is just exactly the same as the previous except theres now a lil' baby one with them?

I have a few thoughts on Maushold
1) They don't actually evolve. They just use the evolution mechanic to give them a chance to finally stop having to hide their very real child.

2) The baby Maus's is more like the second head on a Weezing than an actual baby. Perhaps more like when a real world hydra buds off, the parent hasn't died. Even the pokedex says nobody knows for sure how they babies are related (again maybe not actual evolution)

i'm calling the pokemon police on you bob

See that's the thing!

When I die, because Ix swatted me with a dozen Officer Jennys, what is my kid going to expect?

Do they think I'll suddenly reappear in a flash of light, but this time I have an extra head and some punk rock outfit?
What happens when stage 2 evolution me doesn't show up? What kind of abandonment complex will that create?

Pokemon has set up the expectation that when your longtime partner kicks it, it'll be immediately replaced with a larger, much scarier/angrier version of itself...I'm not sure that's a healthy expectation to set up regarding death.