You have absolutely no proof of that -- to the contrary, many people tend to get more conservative as they get older, which is why so many of our older relatives tend to be hardened racists.
Those who are rarely -- if ever -- exposed to people of other races and cultures have no reason whatsoever to become less racist as time passes, as exposure and travel are often the main reasons why people change their racist and/or bigoted views.
https://www.vox.com/2016/7/1/1205162...nce-psychology
I've dealt with that kind of thing more times than I can count -- think the worst (non-violent) one was when some girl asked one of my USC roommates to ask me to leave my own apartment because she didn't think I was supposed to be there at the party he was throwing.
Then she asked said roommate to ask me if I could stay in my room while she was there at the party because black guys made her "uncomfortable".
Ironically enough, I don't even stress those kinds of situations anymore because they aren't even moderately life threatening -- so long as cops aren't involved, I can handle basic racism with no problem.
Same thing happened when I was living in Westwood and some guy walked up to me and told me that he had seen me on a wanted poster (because there were "thefts in the area") and that I should leave if I didn't want him to call the cops -- I told him to call them if he wanted to, but that's exactly the kind of situation where an unarmed black man can get beaten or shot just become of some random ignorant racist.