It's the reasonable thing to do.

It is extremely frustrating after waiting through the queue, to get in game just to d/c, and be forced back into an even larger queue. Even more frustrating is getting into a duty after waiting some time, and then getting the d/c. That's not fair and that's certainly not fun. It's not for the player who d/c's, or anyone else in that duty that's now short a player. Heck if the wrong people d/c from a BA, DRS, or a static, it might be the end the run for that group.

SE needs to focus on what they can do now to help ease the frustrations of their customers. This is another way to do that which doesn't require new hardware. Especially with the new raids soon, this would be a much appreciated change by all in the community I would think. The queues aren't going away like most thought they would. Primetime weekday mateus is still over 2.5k and that's a low pop world apparently.

This is standard practice in just about every other MMO popular in NA I think. It's not realistic to fix all disconnects, so this is a nice compromise. WoW's had it since vanilla, but I but doubt the game studios like Blizzard are just being nice. There are some technical benefits such as less strain on their hardware when reconnections are spread out over some time. If there were any downsides I doubt they would do it that way, but if you think of any feel free to share.