It makes you wonder why Mt Gox liquidators would need to make the repayments in several batches rather than in a single lump sum. The only possible reason I can think of why they'd do this is if they do not have enough money to cover all of the creditors who have filed a claim. In such a case, where do they expect to get the rest of the money from?
The repayment plan has been settled for ages, they know how much money they have, and they have already sold all the coins necessary for the fiat reimbursement so this leaves only the coins for which they've already set the fraction at which they will be paid back.
The money as agreed is there, it's only the actual payment process that is taking that much time, DaveF covered this nicely.
Funny thing, although the previous liquidation did happen at lower BTC prices, they still managed to get a 4x on the current price for BCH, so for some getting their coins next year might be better than getting them in 2020, if these people wouldn't, of course, depend on that money for a living.
The one I truly wondering is how those creditors could cover up all the expenses of this refund plans since for sure there's a lot of people will claim their part and this is so huge, also the question there if they still have enough money to complete this refund to all affected users.
Everything you want to know is here:
https://www.mtgox.com/d/04y7ivbnz5gw.pdfAnd indeed, it's everything!