Yep, well whether that behavior was intended from the start, an unexpected result or just the description they never bothered to correct I could not tell, but if I am not mistaking and it has always been like this (saga aside) Daily login reward reset at 00:00 UTC and Daily challenges reset at 09:00 UTC (which happens to be same time as RF reset time).
But now that I think of it, that tip of day you are referring to, is probably only about Daily challenges and the rewards which come by completing them (some silvers, green crate…). If that’s the case it all makes sense and Daily login reward only being on a different timer.
This is the first occurrence where we actually had to use one (with the buff) to open an other, and it actually came out as a fix for lower level players who could not attend RF (< lvl 80) and therefore never open those Daily login anniversary crates. Before that fix we could only open the anniversary crates with the buff by completing RF and in that previous situation it did not even matter if they were synced or not. I think that’s why.