Think about it: how would your device identify that nothing else is on that network (the hotspot). It would issue ICMPv6 messages asking who’s there. iPhone hotspot is ipv6 supported nowadays (it didn’t used to be the case).
I’m not sure how this would look. The iPhone has a lot of things on IPv6. They show as interfaces, one interface is the WiFi but then there’s a whole stack of other interfaces that bridge into cellular / WiFi / Bluetooth (as required and often simultaneously).
Namely:
lo is the loopback interface and has IPv6. This allows things to talk back to the iPhone (ie talk to itself)
en0 is your standard WiFi and supports IPv6. On iPhone 15 it supports apples network thread network so often has an extra IPv6 on top of the usual ones.
PDP_IP1 through 10 (yes 10 interfaces) is cellular data. This suggests there can be 10 ESIMs in my mind but I know the limit is 8 so perhaps the other 2 are reserved for say satellite emergency calling / emergency calling which can route via peer to peer and onto any carrier network generally. These have IPv6 addresses when active.
p2p0 is a point to point link (usually used for VPN but also data transfers). As I understand it’s mainly used for “personal VPNs” vs ones setup by say a network admin that are often “device” level. These use IPv6 where ever they can.
stf0 is a “six to four” interface (IPv6 to IPv4) this tunnels IPv6 over networks that don’t support it and are ipv4 only.
gif01 is a software interface that’s not always there
bridge0 is a software bridge between all interfaces to allow traffic to flow as required across the various networking interfaces
There are more utun interfaces - one of which often comes back as nexus and IDS501 - these are network agents that handle traffic and relay / move it around it based on triggers so it goes where it needs. These interface with the bridge.
utun0 is used for “Back to My Mac” and Airdrop. Back to my Mac is sunset but there’s still some traffic that appears to query services as back to my Mac used too.
awdl0 is Apple Wireless Direct Link (Bluetooth) to other Apple and iOS devices
This is why I say Apple is chatty on IPv6. Connect an iPhone and you’ve got potential for all this traffic to start appearing in various places across networks it’s linked too. I think the point is you can’t avoid this traffic and it’s very “noisy” in a log which is what you’re seeing. Oh and Apple networking is surprisingly complicated. I used to work on a Helpdesk in university and had many people coming in claiming they were “hacked” as all of these mysterious networks showed up in “HE Network tools” app (a great app for info on iOS) which they assumed must be spyware / crazy ex.