It's potentially an issue if we had to cancel closer to the flight date. If the miles had a fixed end date if we cancelled then we'd maybe not risk booking a flight where we need both of our miles pulled into one account. We'd book somewhere closer to home. But if we knew the 2 years weren't an issue for the transferred in miles then we could book further away.

I'm always trying to be aware of cancellation conditions after Covid! Not that something like that will occur again soon (hopefully!) but it did make me much more aware of what happens if we need to cancel anything and whether we lose flexibility.