this weekend was very eventful in e-sports as in an unexplained step ESL has decided to ban a large number of players (including some top teams) using even completely legal mods from ESL for two years (from e-sports) and for one week (in the game). The mods that the players were banned for include XVM, Aslain's pack and Oldskool mods.
Previously, ESL banned the use of cheats (Warpack etc.) and mods that are forbidden by Wargaming using this list (see "Creation of derivative works" section, points 5.1 to 5.10).
When asking ESL support about the incident, the players were simply told not to use any mods and that nothing can be done about it. Yesterday, ESL administration issued a statement that the bans were legit and that they won't be overturned. The reason this happened was that WG or ESL staff developed and issued an anti-cheating tool (external resident software) that detected the presence of illicit mods but did nothing - until now, when everyone was simply banned all at once, which means that if you used a cheat mod at any point while the software was running, you'd get "on the list".
As of now it seems clear that the decision will not be overturned and a large number of players will continue to be banned for two years. Several notable WGL PRO players said that they are actually fine with the decision as well - the outrage is not completely universal.
The entire affair once again shows how bad it is not to have clear guidelines about what is allowed and what is not. Some administrators clearly consider tolerated modpacks to be cheating and quite honestly, modpacks that involve things like enemy reload timers, fallen tree indicators and other such things should be considered so. It is up to Wargaming to set the rules more clearly.