Balance differences in older skills/items & mechanics between Standard & Abyssal?

Beginner player here, i have little experience with season-type games.
I know the current latest League is the only one to receive a lot of brand new content & additions (Abyssal).

However i do not understand is the massive 0.3 gameplay update also applied to everything within the Standard league?

The 0.3 update (and patches after it) have a ton of existing item & skill/spell & mechanic & balancing changes - but i do not know did the developers leave the Standard league in some kind of a partially outdated gameplay/balance version (aside from the missing brand new Abyssal content)?

Thanks for explaining and helping out.