Generally speaking, yes. Some rare folks still use catgut strings on their classical guitars.
Your typical acoustic guitar is going to use steel strings, perhaps with bronze windings and other assorted modern choices.
Putting those strings on a classic guitar is going to end in tears. They're simply not built to withstand that sort of tension. If you're lucky, it will just warp the top and the wood will return to its memory point when you remove the strings. If you're unlucky, you're spending a lot of money on a luthier to repair the instrument.
This is off topic, but I don't want to derail the thread too much... Suffice to say, I own an obscene number of guitars and associated gear. When I sold my company, I splurged - especially at auctions. That and I'm an outlier. I've never sold a guitar. I've sold associated gear, but never a guitar. I've given some away but I've never sold one. I've got quite a collection today.
Which is to say, I have some catgut strung guitars just to ensure I can recreate specific sounds. They're really not that good compared to modern strings. It takes quite a bit of stretching and time to get them to properly stay in tune. I do not recommend them to folks unless they've been playing for a few decades. We have much better nylon strings (which come with their own burdens) today.
It's not actually from a cat but they are animal entrails, typically sheep or sometimes goat.
Also, your expensive classical guitar isn't likely to have an adjustable truss rod. The neck will be bending over time. Putting the wrong strings on the guitar is likely to bend the neck. They're precise instruments and need to be treated accordingly.
NOTE: You can get a classical guitar for much cheaper than what I'm explaining. It won't be nearly as good but it will be playable for those folks who want to learn or those folks who are not able to afford more expensive instruments. I would never suggest that a student go out and spend five figures on a guitar.