The question #2 was with regards to reaching gold for the first time. The excess miles from the flight, that pushes you over the threshold, do count towards retaining the gold tier for the first time, provided they get credited automatically (which results in the gold tier starting on the same day as that flight, so those miles are inside the actual gold year and do therefore count).

This is not possible for the subsequent years though (since, logically, every qualifying flight has to be taken inside a specific gold year and there is no overlapping of two subsequent gold years on any day).

shuly Did you by any chance credit miles by the "claim missing miles" form after that last flight, that pushed you over to silver? (those miles could have been from the actual "last" flight or even from any other flight before that, it doesn't matter, only the date of retro-crediting matters).

My own experience is from 2021, but last year there was a member here, who took it to the extreme (flew all 6 segments within a day or two, having already collected over 30k miles) and it still worked.
If the date of the "critical" flight and the first day of your gold year don't match for whatever reason, then those miles in excess won't count.
I also have 3 data points from family members all reaching silver in 2023 and 2024. In all 3 cases I made sure I got the the miles from the flight, that pushed them over to silver, to count for retaining silver the first time (the logic is the exact same). In the case of my wife I actually got the "rest" of miles I purchased for her (500, but she only needed about 160) to count towards retaining silver!

​​​​​OT has a return flight booked btw. From that trip, the first segment will already push him over the threshold, so the miles from the inbound leg are already within the gold year (again provided the dates don't get affected by retro-crediting).