It depends on the definition of "Death" for the franchise.
I'm sure the franchise is far from dead in a marketable sense since SoTN-esque clone indie games are actually doing well, much like the Mighty No.9 situation with Megaman, Fans really want more. From a creative standpoint though, Castlevania is surely suffering, with the LoS games suffering from Identity crisis to the grand crash in story with LoS2, as well as the 1999 fiasco with the later IGA games, its quite obvious that the Castlevania story isn't meant for a large scale timeline but excels with an anthology format. Honestly the simple format of "Objective: Kill dracula" but having many twists and turns in between start to finish was done best with the "alternative" games (Cv64, LoD, and CotM) coming in as standalone titles with a story contained completely within itself.
Going back to the marketable side, the current game market is digging the while enhanced remakes deal, in which Majora's Mask 3D opens up more posibilities. Konami could easily remake Both 64 titles with enhanced graphics and take a page from MM3D in adding a free camera controlled by the C-nub, and/or re-release a "HD" remaster of DXC for the Sony market. Hell, at this point porting the Pachislot games to Mobile and The Arcade to Consoles could make a pretty penny. If Capcom can release Resident Evil 3 times and still make a hefty profit, I'm sure Konami can do the same with Castlevania.
I'm sure this is all spectating around Konami's Eye of Sauron fixated on Metal Gear, not having anything against MG, but they have Soooooo many IPs to expand on it's not even funny, and I'm certain even a remake of a lesser known title will get recognition, look at Strider, It's original 2 games have been pretty much forgotten by the time it released and it did pretty well, It would be really cool if Capcom decided to make Beat-em-ups again, a new Final Fight and Captain Commando are long overdue, But getting back on point, even if Castlevania has be ignored for a few years it would still be nice if Konami expanded a bit more, but it would be great if that expansion involved Castlevania since this would be a perfect oppritunity to do alot of out of the box experimental gameplay elements to define this gen's Castlevania.