Yes, it will flow more than enough. The 80 mm hole in the top has 2.5 times the area of your 50 mm carbs. Even if we assume a 10% flow loss due to the right-angle on the front—which would be a massive and unlikely loss—you’re still getting 2.3 times the airflow of your 50s.
On our system, we’ve designed a proper clamp setup that lifts the base of the filter up and eliminates the adapters blocking the 80 mm inlet. This removes the restriction found in other systems.
I run this setup on my race skis with 48 mm Novis, and the jetting doesn’t change at all between having the top on or off. If it were a restriction, the ski would run lean with the top off and rich with it on—but it doesn’t. That tells you everything you need to know.
The stock mesh will still fit so you can also run a single mesh over the carbs if you feel you want to—I don’t, but then again, I also make sure I don’t have bolts flying around inside my ski.