As I understand it ( had already left OSH when it happened) those 2 accidents yesterday occurred outside of the OSH “controlled “ area. The UL procedure has changed this year and apparently one of the 2 did not follow the NOTAM , as to the T6 , above the lake , not really directly OSH related .
I fly/flew ro OSH , and if one reads and follows the NOTAM and its procedures nothing happens ,the last collision between 2 aircraft attending was in 1974 when radio was not mandatory. Seen the number of aircraft attending , flying in , landing incidents accidents are bound to occur but all in all it is relatively safe to fly in for an average GA pilot .
On the airshows ( the ones done by professionals) the last years i attended ( 2017 and 2019) it was pretty close sometimes, this year it was totally different , only one set of aircraft at the time , lot of blank times between the aircraft shows , “ safe “ maneuvers, no cowboys anymore like Jet Waco, Sukhoi 110 , or some private military jets . I wonder if this was the consequence to the B17 crash in Dallas last year.