Assuming they started off as two of them 2000 years ago and Fibonacci was right about rabbit breeding habits (and Olympians mature in 4 years time and don't menopause before the age of 2000). We'd have 139423224561697880139724382870407283950070256587697307264108962948325571622863290691557658876222521294125 (500th element of the Fibonacci sequence (2000 years / 4 years = 500 Olympian breeding seasons). There'd be plenty of them to name planets after.
It's like in No Man's Sky where you start out giving thoughtful names to every planet you come across, but after about twenty systems you're running into similar world types and color schemes that evoke the same names you've already used, so you just stop giving a shit and stick with the names the planets are generated with.
There are approximately two metric shit tons of planets. I assume scientists have better things to do with their time than to sit around and think of names to give to every single one of those.
I just assumed all the ones we would actually hear about would get named more regularly. But I guess if they're talking about a specific one, this would happen. I never really thought about how many must really be out there, but now it seems obvious.