WalsallJack: out of all the "friends" I play on WGT with, none of them had an increase in their average...none of them.
You may note that only TLs were affected, and the increase depended on their averages' status.
Common opinion among forum posters is that up to 300 of their best scores have been deleted from their average's pool. This affects seasoned TLs less because they have a plethora of very good scores. OTOH, it may have risen the average a lot when a big spread of scores was in the mix.
Our best guess today is that, together with a 58 average, at least 200 more scores are necessary to tier up to Champion.