It's hard to predict attendance for all of the US and Europe, but I can see some things for New England.
F1 is strong in CT and NY. It seems to be surpassing WGT-R and foam WGT is just plain dead and lost to the history books. I'll miss foam WGT more than most people. Last week Madness had 3 of us in WGT-R and 3 F1 drivers due to holiday distractions and other trophy races within driving distance.
We ran them together as a combined class and it was a huge success. All the heat races and the main had all cars within 1 lap.
17.5 sedan is down a bit on the local level and USGT is up. Some of us are also caught up in the booming carpet/turf off-road racing. 2wd buggies on looped carpet are just too much fun to ignore.
Stock 1/12 scale still has a pro level following, but number are low. Mid-level 1/12 is not happening even though at least 7 local guys have 1/12 scales "almost ready", but none of us owns a tire truer. LOL
The F1 seems to be mostly Xray X1 with Reedy 25.5 (w/12.3 rotor).
WGT-R is a new class for us in CT, so we are running informal "Jun rules" that are a gentleman's agreement to run outdated 13.5 motors , average batteries and charged at 10A or less. We don't tell the pro drivers that show up with Team Scream 17.5 motors and 40A chargers. The result is similar lap times for the top 5 average.