Should a "good" Ph.D. student still get some strong supervision?
Some advisors have a style of viewing supervision the same way ER doctors look at treatment. The key word is triage. Where there's a need to make things okay, he/she will be there. My advisor had the same viewpoint as he was very busy with other work and saw our meetings more as a checking-in as a friend than supervision.  I thought that when all the other students graduated, he'd give me the same amount of time as they got, but that was untrue. He continued with the same amount.

I asked him about this at the end, and he just said there weren't many crises (there was exactly one, in which he met me within 8 hours to make a game plan with me). Rest assured that your advisor probably is allowing you to create your own research programme and become independent earlier than usually scheduled. This will help your letter from him. From having more of a mentoring friend instead of being strongly supervised, I had an easy transition to postdoc, which is basically how your advisor is treating you now. In my fourth year, I felt almost abandoned. A year into my postdoc, I see that my advisor was the best advisor I could have asked for. 

Seems like you're doing great as an independent researcher and your advisor will give you his input if needed but is curious what you'll come up with on your own. A loose leash is a good thing if you're self-motivated.