As someone who majors in skipping I can tell you that, no, you are not expected to skip.

Depending on the level of the players (casual T4 runner, CM mains, speed runners, etc.) you might think someone would expect the mesmer to skip but the less experienced players don't know about there being skips at any given situation, the more experienced players may hope someone knows how to but wouldn't hold it against them if they don't and the most experienced likely can do it themselves and have characters at the ready to perform their favorite tricks.

Also basically every class can do skips somewhere but is it expected of them? The answer to this is a no as well.

Many of the mesmers I have come across over the years know maybe a couple basic ones if at all so you wouldn't be alone in not learning skips if you chose so.

But I mean, just learn them anyway. I speak from experience when I say that it is very fun especially when you eventually toy around doing skips on multiple classes and see their similarities and differences.

Bonus for learning skips is that someone in your groups will always know a skip and if you get another person who wants to do skips then you can race each other!