How is that different from what's being done now? There is a standardized way of determining when leap seconds are going to happen (they always happen on June 30th or December 31st when the deviation reaches about 0.6s), there is an authority that determines and announces it (the International Earth Rotation and Reference Systems Service) and it is, in fact, done by causing the last minute on the day in question to have 61 seconds instead of the usual 60.

The complication is just that there are a whole lot of systems out there that assume that every minute has exactly 60 seconds with no exceptions, so you end up with crazy workarounds like smearing to hide that 61st second from such systems.