I have a website with 4 addon and sub domain. i have to suspend whole account so i have suspended main website but i can see main site is showing 404 error page but all other sub domain and addon domains are loading properly. it means only main domain suspended. now think one of our user hosting account suspended but he/she added addon he/she can use this addon domain life long free without paying a single penny.
whmcs module also do same thing suspend main site only not whole account or child/addon domain.