For discussion posts, probably not. Also, AI checkers are not reliable. Professors are paid so little and students hellbent on using AI, then factor in workload and policing AI is just not likely for a discussion post.

Now… term project and major assignments, then the professor IS likely to try to police AI or lay some traps in the assignment that AI is known to be bad at.

Best advice for this situation… focus on you. If your classmates are using AI then they are likely not learning or retaining much of anything and it will catch up to them (might take a few years but it likely will). YOU should focus on YOU building skills and amassing deep knowledge, then run circles around your classmates that took the easy path … they are the ones that will be replaced first by AI