Yes, we use the File Poller using dynamic file names in a couple of pipelines and it works well for us.
It may just be a typo in your question, but you need to make sure you use the correct case-sensitive syntax to generate the dynamic file name (See https://doc.snaplogic.com/wiki/display/SD/Date+Functions+and+Properties for Date to-string functions).
As for the success/fail question; the File Poller is designed to poll a file path until a matching file exists, so it will almost always succeed unless the file path becomes unavailable (someone please correct me if I’m wrong). So, depending on your business requirements, if you need to fail, throw an exception, or send notification on a late or missing file delivery, it may be better to use a File Reader on a Task Schedule rather than a File Poller
