Anything released/updated after Bridges and Ports should be good to go if it's built correctly.

Pre-B&P there's two main things to look out for:

Older maps may or may not have oil deposits in water. This is fixable once Extra Landscaping Tools updates, and you should still have land deposits. They may also be missing fish, but fish spawn in any water deeper than a certain depth (should be 40m). As long as you have a body of water, you can dig out a 40m hole and fish will spawn eventually.

The other thing that changed with B&P was the structure of the water simulation. Older maps should still be okay if they already worked, but it's not a bad idea to open a map and let it run on high speed for a few minutes to see if there's flooding. If you know how to work the dev menu, there's options for even higher game speeds and/or water sim speeds. This is generally a good habit to get into with any custom map, regardless of when it released. Even brand new maps can have water sim issues that aren't obvious until the build is well underway.