Hi,
From that alone, I’d assume yes. As each machine would be independent of the other, running its own copy of the code.
You could easily confirm by logging a message, then checking e.g fly logs. See if it’s there twice.
Fly doesn’t have a managed cron service that I know of 
There are a variety of threads about crons. They do have scheduled machines which you could maybe use instead …
Or Supercronic:
I don’t know what the recommended approach is right now . Else you are stuck using something like this from Google 
Cloud Scheduler | Google Cloud