No, LinkedIn hasn't given up on its quest to be as cool as the other kids. The career-focused social network is introducing Reactions that behave not-so-subtly like Facebook's, just with a decidedly business-like flair. On top of liking and loving posts, you can use "celebrate" to pat someone on the back for a new job, "insightful" when they've posted a nugget of wisdom, and "curious" when they get you thinking. Not surprisingly, there aren't any potentially negative Reactions -- we can't imagine a co-worker taking well to a "laugh" response to their big presentation.
However much you want to praise your business pals, you'll have to be patient. Reactions are rolling out now, but it won't be until sometime in the "coming months" that they'll be available to everyone around the world, both in mobile apps and on the web. Look at it this way, though: whenever they do show up, they'll give you an easy way to acknowledge someone's career update without having to write some generic platitudes.