It seems that during the upgrade, the /etc/config/network config on my Turris 1.0 got modified. I lost all the switch_vlan sections and some other parts got rearranged as well.
I also have a secondary Wifi card but the /etc/config/wireless config got modified as well, so the path attributes which pointed each config to a different card were lost.
All in all, not that great an update for me 