I always find it weird when people are hoping that Harry will be put aside and made irrelevant as soon as the Queen dies... especially when said people adore the Cambridge family because, after all, the future of Charlotte and Louis will look a lot like their uncle Harry's.
I am not sure what example William would give to his children by casting aside his own brother who has done nothing that could be compared to what Andrew is accused of.
I don't think it is a matter ot casting anyone aside, but, if you follow the other non-British royal forums, there has been a clear trend, both recently and over the past years and across several countries (Spain, the Netherlands, now Sweden, and, to a lesser extent, Belgium), to slim down their respective Royal Houses. That means not only cutting down on the number of RF members who are HRHs, but also cutting down on the number of RF members who get public funding and/or take up official public duties on behalf of the monarch.
As the son of a likely future King Charles III/George VII and the brother of a likely future King William V, there is no doubt to me that the Duke of Sussex will be a full-time working royal for the rest of his life. If, however, the UK follows the current European trend, I don't see an HRH style or an official public role for Harry and Meghan's children, which means for example that King George V's 1917 LPs will be probably replaced with new rules. I also think it is possible that Harry's children will have to support themselves either with their private family inheritance or their work, or, most likely, both.