I'm thinking like the main reason why David de Gea couldn't find a team for himself is his high salary expectation. He couldn't reach an agreement with Manchester United because of this reason. I thought that maybe Bayern Munich would be keen on signing him but they didn't want to go for him either. They preferred a young talent named Daniel Peretz instead.
If Bayern Munich didn't spend a lot of money on Kane transfer then maybe they would have made an official offer for de Gea who knows. Because it took them even a long time to reach an agreement for Kane transfer at a price as favourable as possible.
They wouldn't have paid a lot of money for Kane's transfer, but the Tottenham president turned out to be very stubborn. Maybe they gave up on the De Gea transfer when they gave him more money than they expected. I think a goalkeeper of De Gea's quality would strengthen Bayern Munich. I think De Gea will sign with another team during the interim transfer period.
I remember David Degea had to accept a reduction of salary just to remain at Manchester United but they decided to still let him leave as free agent when his contract expired, so if Bayern had made a move for Degea maybe he would had considered moving over there, they're the biggest club in the Bundesliga and would offer him a chance to be in the Champions League so i so no reason why he wouldn't had considered taking a paycut to join them, Bayern Munich didn't show much interest if not they would've got Degea.
However Kane's transfer fee shouldn't had been used as excuse for not getting Degea, cause they would got him if they were really serious, moreover he's a free agent and would've be very costly like when he had a team, and Bayern Munich sold some players after buying kane so they had extra cash to spend of Degea.