Update 9.17.1 brought a lot of changes to several vehicles, especially German ones. When these changes were finally introduced to the Live Server, a few things started to stand out. Several Russian Youtubers and other Contributors have pointed out that several of these vehicles who received a buff, started to stand out and this increase isn’t good.
“Currently we are collecting statistics and information actively. After that, we will take measures accordingly to correct these tanks. One of these examples is the Maus, it shows a big change on it’s statistics and performance.”
So it seems Wargaming decided to show some love for the German vehicles and now they changed their mind. I think these changes on statistics most probably are reflected by the fact a lot of good players started to play with these vehicles again, and even average players now can do some decent games with them. Time will tell if these statistic changes were just a “glitch in the matrix”, of if these vehicles really are in need of a nerf.