It makes me feel like missing out if I level up when the event is not there. It’s annoying only to level one day a week “Ooh, nice! Pulled the Dr Doom I hoped for. Better shelf him 5 days until the next Level event!”
its not only once a week its more like twice a week.there is Arena Wins, Hero Use, Event Quest Completion and Level up.thats 4. there is 7 days in a week.they appear in a random order but always run in a group of 4. And will never appear twice in a row.you may get AW, HU, EQC, LU, ......HU, LU, AW, EQC,..... AW, EQC, HU, LU..... AW, EQC, LU, HU..... for example.but you will not get AW, HU, EQC, LU, ..... LU, HU AW, EQC,..... EQC, AW,HU, LU..... AW, EQC, LU, HU.....meaning that once one appears it will possibly appear again 2 days time, but it will never be more than 7 days between each event.Statistically you will see it on average once every 4 days or twice a week.there will be many more weeks that contain 2 then weeks that only contain it once.