No, there is generally no requirement for you to advise any company about how you ensure your medical is maintained. All the company cares about is that you have a valid medical and that they can work around any restrictions you have. How you go about ensuring those restrictions are met (through a monitor and ultrasound in your case) is between the regulator, your doctor, and you. The reason I say "generally no requirement" is because there are some airlines who have doctors on staff that will complete a pilot medical for them - rather than the pilot going to their own aviation medical examiner. In those cases, because the company supplies the doctor, it does fall on it being their business. But that shouldn't affect your ability to get or not to get a job, as long as the medical and its restrictions still allow you to do the job they need you to do. The doctors should not be talking to flight ops outside of "pilot x is medically fit to fly." Anything other than that borders on a violation of doctor-patient confidentiality and points to a company I probably wouldn't want to work for anyways.
Now, onto Ryanair. They're an airline, not a business aviation company. In your original post you suggested a preference for business aviation, which is why I suggested in my first response that you find it harder to land a job. If you do expand your horizons to the airlines, you'll find it easier to land a job. You may still have to describe how else you can help the airline given your restriction, but that's not as big an issue with an airline over a business aviation company. In fact, if you have a colleague who is going through that process and they are ultimately successful, they'll be the best resource you have as to what steps to take, especially given their case seems more restrictive than yours. I would strongly suggest you keep in regular touch with that colleague.