I have asked question and it was closed because it mentions iPhone and it is commodity hardware. But it also relates to how mobile operator interprets traffic from iPhone HotSpot and it also relates to ANYCAST BGP. If it would not be answered at networkengineering.stackexchange.com then it would not be answered at all. It is wrong place to ask about ANYCAST BGP at SuperUser.
But it also relates to how mobile operator interprets traffic from iPhone HotSpot
Unfortunately, questions about networks you do not directly control are also off-topic on NE. What a network operator does on its own network can only be answered by the network operator. We could only speculate or guess, and that is off-topic.
it also relates to ANYCAST BGP.
We can explain about anycast (search for that on the NE Q&A site, and you will find explanations), but we cannot give you specifics about what the various sites are actually doing, or how the network operators are receiving prefixes.