Please do not worry about being referred to Oncology. I have been in their care for nine years and expect to be seeing something of them for many more years.
My advice is to get all the detail you can of what they know and suspect (both are important). Ask to see the scans. Sometimes there are perfectly good explanations for suspicious areas - old injuries, wear and tear and so on. Only where the radiologist is certain of Mets should you be concerned. On this, if it happens, there are lots of treatment options. When one fails (if it does) there are these days lots more to try. Your husband is where I was a few years ago.
Do remember the golden rule - in prostate cancer there are no rules, in other words, every case is unique and the solution that works best for your husband may be an unexpected one, but a solution there will surely be.