Judging anything about trends in video games by looking at either fighting games or shmups is kinda like judging trends in automobiles by looking only at muscle cars. They’re SUPER CRAZY NICHE products that cater mostly to enthusiasts.
That said, I agree with the disagreement on shmups - bullet hell games are NOT actually ‘faster’ than most older games, but, in many cases, actually SLOWER, just more “busy” (more things going on at once.).
Fighting games…welp, Street Fighter 4 is markedly slower in many respects than earlier versions of the game, but the latest iteration of BlazBlue is markedly faster overall than previous versions, so I don’t think there’s a trend here either.
FPS games, once again, have slowed down significantly - CoD is a much more sedate game than Quake. 
So considering that ALL of your examples are SERIOUSLY OLD, I’m not at all convinced there is a trend here. If anything, in recent years it’s the opposite, because games are struggling to gain wider accessibility, and so things like extreme twitch reflexes are being de-emphasized. This might’ve been a trend in the 90s though. 
FWIW, how ‘fast’ I like a game to be is tied very tightly to how the game works, and it’s a super hard thing to measure even across games in the same “genre”. For example, fighting games - Street Fighter 4 is a very ‘fast’ game if you look at the speed of attacks - some come out in 3 frames, and even things like overheads that you might be expected to try to react to come out in 17 frames or so. Compare that to Blazblue where the fastest attacks are 5-6 frames and most overheads are in the 24ish area. But at the same time, SF4 is a very slow game, because each character walks pretty slowly, has very limited dash options, and jumps are kinda floaty, whereas in Blazblue most of the cast can run, fly through the air with impressive speed, etc. So while attacks in Street Fighter are fast, movement is slow, and Blazblue is the reverse.
So yeah. Stuff?