24.10 for R7800 will use DSA like the whole ipq806x target.
You will need to re-do the network config by hand.
Best is to get new defaults from the system, by not having network and system files in /etc/config at sysupgrade. Then OpenWrt generates new default files for you.
You can just rename the two files before sysupgrade, so that you have them for easy reference. Just rename network to network.swconfig or network.old or..., and same for system.
(I have been testing my 23.05 and master builds by keeping two versions of system, network and sqm config files, and have just been copying the correct one into place before sysupgrade.
Why those files: Network has network settings, sqm refers to wan interface with old name, and system has the compat flag for sysupgrade.