Another dimension of the "it depends" response to this is seniority.

If you're relatively junior, or will appear relatively junior based on your resume, don't express strong disagreement, but rather eagerness to learn. The team wants you to be someone who can contribute, and help them make progress towards their current goals. You're not there to re-evaluate decisions about their stack based on the glimpses get you get during the interview process.

But if you're quite senior, the team perhaps wants you to help them level up or improve. Agreeing with everything would also suggest you don't have something new to contribute that helps take them beyond the track they're on now. Don't disagree without a good reason, and be able to explain your thinking. Ask questions before you arrive at a position. Understand why the fence is there before you advocate its removal. But insightful, constructive "disagreement" can still be a way to demonstrate the value you'll bring.