Legality regarding Pokemon Go transfers, based on Date.

[theSLAYER]

Not every Kanto Pokemon were available from launch.
Given that:
1. Pokemon Go transfers to Let's Go retains dates
2. You can't change your mobile phone date to change the date of capture on Pokemon Go. (the date is set by server side; you can change your phone's timezone, and the date captured should reflect a similar change, cause the epoch timestamp is stored on Go's server)

These dates are the earliest point you can get the mons.
I'll be updating this list as I collect more info. Do note that raid mons were not always available past the release date.

edit: No longer updated.

 

[TiffanyDarlet]

i know this is old, but i recently get Let's GO eevee, mew can be transfered from GO to Let's GO?

[theSLAYER]

Just now, TiffanyDarlet said:

mew can be transfered from GO to Let's GO?

no.

[Poke J]

Just now, TiffanyDarlet said:

i know this is old, but i recently get Let's GO eevee, mew can be transfered from GO to Let's GO?

No, mythical and certain event Pokémon like hat Pikachu can not be transferred.

[TiffanyDarlet]

aawww, well thankyou for the answer