It's possible but somewhat amorphous.
Is there love? Or are they "In Love"? ...there's a difference.
Bryan Fuller explained to TVLine.com
TVL: In the first two seasons, their relationship — or the possible romance between them — was mostly between the lines. In the last few episodes of Season 3, though, it started to feel a little more like, “The Incredibly True Adventure of Two Sociopaths in Love.” We’ve had Bedelia asking Will if he aches for Dr. Lecter. Will and Hannibal’s “goodbye chat” felt like a breakup. To me, it’s all seemed more overtly romantic, and I just wonder if that’s what you’ve been trying to project.
FULLER: It felt like we had to s–t or get off the pot, ultimately, because there had been so much going on between these two men that when Will asks, “Is Hannibal Lecter in love with me?” it is very much about death and the romance between these two men. There is a quality to connections that go above and beyond sexuality. You can have this intimate connection with somebody that then causes you to wonder where the lines of your own sexuality are. And we didn’t quite broach the sexuality. It was certainly suggested, but the love is absolutely on the table. There is love between these two men, and confusion between these two men. We had to articulate it, and the idea for a [potential] Season 4 was an interesting continuation of that, as well as a subversion of it at the same time. So it’s strange to look at [this week’s episode] as a finale, because part of me believes that the most interesting chapter of Will Graham’s story is yet to be told.
Since S4 is not yet available (assuming it ever is), it's possible this will be explored in that season.
Fuller to The Independent
"There’s an interesting next chapter in the relationship between Will Graham and Hannibal Lecter that would be fascinating to unpack. I’ve shared it with the gentlemen and they’re both keen on it."