It works so long as you’re not trying to create separate networks. When/if you decide to start with some vlan madness and such the AP likely won’t work for that, unless it’s fancy and can do multiple SSID on separate clans, but most WiFi/router combos don’t go that far.

Basically the new firewall/router box becomes the boss of everything done ng DHCP, likely DNS relaying, and all the monitoring. Simple and efficient, just wouldn’t go hosting public services with the setup since there’s no ‘DMZ’ to keep it separate from you personal devices.