Does the expansions affect leveling

I played Guild Wars 2 when it still was pay-2-play. Now I've decided to come back and give it a try again. I noticed that there are two expansions and I was wondering if I should pick them up right away. I am reluctant to doing it since from what I could tell, all content in the expansions (except for the extra class) just become relevant once you reach level 80 with one toon. Since I don't have a level 80 character and I wish to level, I'm debating if I should buy the expansions now or wait until I reach 80.
Does the expansions affect leveling in any way or will the leveling experience still be the same weather or not I have them?
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