A couple of observations.
Dan Wheldon drove 98 in the Indy 500 in 2011, his number at Las Vegas was 77. There's some background as to why he swapped with his team mate Alex Tagliani but I honestly can't recall what it was, maybe some team/sponsor deal. I'd prefer to remember him in 98 or 25 which he ran in 2005. I don't associate 27 with Gilles because he died with it.
NASCAR didn't retire 3 but it remains the teams to use, Richard Childress decided not to use it until his grandson Austin Dillon came up. Dale Jr did use it in a Nationwide race in 2012 I think which created a bit of attention. When Kevin Harvick came in as Dale's direct replacement, the car number was 29 which remained Harvicks until he left for Stewart Haas and took 4.
Who knows what the FIA would have done in say 1994 had driver's owned numbers, maybe they would have retired RR & AS, maybe not. Perhaps they feel having utterly dropped the ball at Suzuka and then wasted no time in dumping all the blame on Bianchi who of course was in no state to respond they should show some consideration & remorse.
Having said that, a period where the number isn't used would have sufficed imo.