Having Cyrus remove Strahd's portrait

I had this idea I wanted to share with the community. There's been a lot of talk about planting Strahd's armor somewhere for the PCs to pick it up so that it may be used against them during the final confrontation. I love the idea but I also like to be fair. I feel like there should be clues given or an opportunity provided for players to avoid this. This is where the dinner with Strahd comes in. I'd have the PCs stay the night. They'd be given Escher's quarters in the tower. This means they'd naturally get to see Strahd's portrait next to the door. But that's too easy. By this time, Strahd's already plotting the armor ruse, so he ordered Cyrus to remove the painting. Only thing is, Cyrus' been busy prepping for the dinner and he only remembered to do so at the very last minute as the PCs are being ushered into the dining hall. This means PCs would only catch a glimpse of Cyrus carrying a painting down the stairs while Rahadin's casting a scornful glance at him. Also upon returning to their quarters they'll notice the discoloration on the wall clearly indicating that a painting had been removed from there. Now they have the option to slink around, explore and perhaps find the portrait (in Cyrus' junk chamber). I feel like that's fair. What do you guys think?