As a DJ doing salsa+bachata not long ago someone asked me for marcarena ... requests sometimes are tricky.
I take requests as long as they are sensible and according to the vibe. Yesterday I was asked a song at peak time that I understood was not good for peak time so I told the guy I plan to play it but more than an hour after and made sure to point at him just when I started playing it.
Later he came to thank me.
I would not play a song that I don't know though. If I get a request that I don't know, I write it down and tell the person I won't play it this week but I wrote it down and if I like it I may play it next week.
I love to play recent songs, although not every week I play new songs there are songs from 2025 that I played over 20 times already. Unfortunately some dance teachers that run latin nights prefer to play the same songs they started playing 10+years ago. I guess it is because it is easier for dancers but I find it boring and I don't see myself playing the same 70 out of 100 songs every night until I decide to retire...
Recently I got one of those dance teachers asking why was I playing so many new songs, I was confused,
Me - What do you mean?
He says- This song it is new! (Christian Alicea - Hello, What's Up)
Me - No, it is not! It debut in March, I've been playing it regularly since last spring, you should come more often

On the other hand, there is a recent post (december) from someone who when to festivals in europe but didn't recognize the music. I understand people who like to go to a new place and the sound is familiar but I believe there must be a showcase of new/recent music and if the crowd likes a new song I keep playing it.
Generally, I avoid playing above 102 bpm salsa. If I really want to play a song that is faster than 102 bpm I usually reduce the tempo to 102 bpm. Also songs longer than 4m30s I tend to do a shorter edit. Our crowd is made of definitely not professionals and I don't want them to get tired too fast.
Fortunately me, the dance teacher I work with and our crowd don't like romantic salsa much, we got bachata to do romantic dance anyway.
Based in Didim/Turkey