Even if the deal was for $100 million, surely that wasn't money in their pockets (minus tax) but would also include production costs to make the shows, pay the production staff, rent the fake dream home that the shows were filmed in, etc. And that would be for a number of different shows to be produced over a number of years, with all sorts of terms and conditions in the contract, e.g. a new show would only be funded subject to reaching certain viewing figures for previous shows or subject to certain costing or content requirements. The deal was with Archewell Productions, not Harry and Meghan.
Yes, the idea that Netflix wrote a cheque for '$100 million, to the account of Harry & Meghan' is ridiculous. I'm sure they'll have earned a fair bit from the NF deal, despite their failure to produce, but it won't have been anything close to that amount.
I don't think they're broke by any means, as some people believe.
I guess there are different levels of 'broke'. Certainly they're rich by normal person standards, but they were the poor neighbours in Montecito. Also, Harry is going to have massive legal bills, both from the failed judicial review and the ANL case. And other than inheritances and investments, it's hard to see where any income is going to come from in the future.
Something must have prompted the Great Return. It may not be money, but I'm sure it featured on some level.