As a huge Monster Hunter fan (500+ hours invested) I'm pretty optimistic about this. It's good to see the team trying out new things and ideas. If you want the old style Monster Hunter there is plenty of that with Generations and XX. In fact, there is so much of it that it got a bit tiresome. It's time to change things up a little. If it turns out some things don't work they can always dial it back a little with 5 or whichever sequel, but I prefer they at least TRY.
There are some great ideas in the trailer imo. Tracking, the hookshot, but most of all, the open environment playing a big role. Natural traps, water washing things away and other neat stuff about using the environment to your advantage. The game also has this more organic feel to it, with for example monsters attacking and even eating other monsters.
It's not like I don't have concerns. The world seems a little too bland. It's also weird they didn't show combat (even in the extended gameplay trailer) and I agree some of the animations look a bit off. Overall there seems to be a lack of joy and wackiness, which is part of the core DNA of the series. It's still a bit unpolished or even unfinished (animations/no music?), but there is potential here.