I can relate, but I've been burnt out on the formula for much longer. I did not play SotN when it first launched, but I did get all six of the portable Metroid style GBA and DS games on launch... but to be honest, by the time I made it to Dawn of Sorrow, I had already played the previous 4 games of that style so many times... that combined with the fact that Dawn reuses a lot from Aria, it was the first game in the Metroid style lineup that I never finished due to formula fatigue.
I did end up finishing Portrait of Ruin, but I also never finished OoE, I just felt too over the formula, even if OoE did try a lot of new things.
I needed a really long break from the formula, and the time between OoE and Bloodstained was enough, because I enjoyed my playthrough of Bloodstained when it first launched.
All that being said, I think the fatigue comes more from having so many of those games come out back to back in those days, I don't think there is anything inherently wrong with the formula. And its also easy to understand why someone would prefer the Classicvanias, as what they offer is completely different than the Metroid style ones.
I've got a whole lot to say about Classicvanias, in the form of our game releasing at the end of the month.