Considering Twilight Princess HD did 300K, I almost want to say that's disappointing for Skyrim seeing how much bigger it was. But nah, that's a great for a remaster, and I imagine it will continue to sell well for awhile.
Gears is just the latest in a long line of declining MS IPs. Happened to Nintendo when the 3DS and Wii U didn't match their predecessors. They can come back if MS really gets their act going again (in both hardware and software). Battlefield feels like it should've been bigger given the hype, but it'll probably have long legs. Titanfall, well anyone could see that coming.
BF sold well. The thing I'm looking at is that is sold pretty evenly along both platforms. Including the bundle that MS had. The BF bundle really didn't do all that as far as sales go.