Yes, for me, the desire of top and bottom is always changing. The biggest factor for me is what the other guy(s) is/are interested in doing. I've never dated a guy based upon him being top or bottom. If I like the guy enough to date him, I can easily adapt to him. The 1st bf was strictly a top when we met. But over the years, he started wanting to bottom more, so we became versatile. The next bf was more of a bottom, so I was more of a top with him. The 3rd bf was mainly a top, so I bottomed for him, but after a few years we both would change up and we were mainly versatile. The current bf was a very dominating top when we met. I really loved being a submissive bottom for him. But over the years, even he wanted to being a bottom at times, so I learned to be the dominating top for him. I even had a fuck buddy that was absolutely 100% top and would never ever bottom. We had the hottest sex because he was all about taking care of my ass. But one day after he had fucked me, he asked if I would consider fucking him one time. He was wanting to know what it felt like. So I told him I was versatile and had no problem with that. So I fucked his very tight ass the one time. He said he really enjoyed it but that was the only time he bottomed.
I think it is important to remain fluid in a relationship.