I'd say that every frontend engineer should keep their eyes open for new tech but I wouldn't say that everyone needs to learn AWS.
There was a very similar question above so let me just reuse the answer (DRY, hah!):
AWS (and cloud in general) are going to become more and more important for developers but I don't believe that engineers have to learn AWS. My advice is to always keep your eyes open for new technologies but don't learn things just because they're trending - but once you'll have a use case for AWS, then by all means go for it! You can start here: egghead.io/playlists/learn-aws-lambda-from-scratc…