They might have different standards and I'm not a pilot, but in my opinion having multiple seconds of UI lag in vitally important interfaces is not good enough nor deserves certification.
The safety record for commercial airlines is extremely good per mile traveled as compared to pretty much any other form of powered transportation. At some level I share your concerns about UI lag, but it would seem not to negatively affect safety of flights in any detectable way.
This. The PFD and ND, the displays showing actually important data like the plane attitude, altitude and also another map responds immediately to changes. But the map shown in the video just isn’t safety critical and simply doesn’t matter in the worst case.
Some of that may be due to redundant devices. You're waiting for at least 2 devices to return a reading, and probably a third thing that handles reconciling the results.
The speed of this thing doesn't seem particularly vital either. Everything of interest in a split second scenario is already on-screen; just looking at their speed, it would you a comparatively long time to get off the edge of the map. If you have time to get off the edge of the map, you have time to wait a couple seconds for the page to load. If you don't have time to get off the edge of the map, there's not really a reason to fidget with it.
I agree, it seems annoying, but it doesn't ultimately seem dangerous. I can't think of a situation where you a) need to change the screen, and b) don't have time to wait for the UI to update. And I would much rather have 2 seconds of UI lag to get a known correct response than milli/nano seconds of lag to get a probably correct response. Most of us exist in a world where the response time is more important than absolute correctness.