If I keep my pokémon from evolving, can it still learn moves that were skipped?

Question

Wurmple can learn Bug Bite at lvl 15 even though it evolves into Sillcoon/Cascoon way before that. It's at lvl 12 now but both Beautifly and Dustox learn Gust at lvl 13. If I keep Wurmple pass 13, will it still be able to learn Gust from the move reminder?? (playing Platinum)

Answer 1

Long story short, Yes
However, Beautifly and Dustox won't be able to learn Bug Bite from the move reminder no matter the level, as evolved Pokemon can't learn pre-evolution moves no matter what, prior to Generation 8. Just remember that it takes a Heart Scale to relearn a move in Platinum!
Source: Experience

Answer 2

It depends on what you're asking about.

If you're wondering whether you can grind Wurmple to level 13 and then evolve it into Beautifly/Dustox (at, say, level 15) and then have it remember Gust, then the answer to your question is yes. In Gen 4, any Pokemon can remember a move that they would normally learn through level up.

If you're instead curious about whether Wurmple can remember Gust past level 13, without evolving it first, then the answer to your question is no.

According to Bulbapedia:

The Move Reminder can only teach a Pokémon moves that its species can learn in the game at hand...

Only the species of the Pokemon that learns a move is able to remember it. In this case, because Wurmple is a separate species than both Beautifly and Dustox, and Wurmple doesn't learn Gust at level 13, Wurmple would not be able to remember Gust even if it was above level 15. As of now, this is true for all generations.

Sources: Experience and this

Hope this answers your question!