you could achieve that using mod_rewrite - a single RewriteRule with a pattern that matches those specific paths.

however, if you are serving multiple virtual hostnames on that server configuration you'll need a preceding RewriteCond directive to exclude other hostname requests.

I tried this but no luck

RewriteCond %{HTTP_HOST} ^(www\.)?example\.com$ [NC]
RewriteCond %{QUERY_STRING} ^/?announcements/(.*)$
RewriteRule ^([A-Za-z0-9]+)$ https://$1.example.com/? [L,R=301]

RewriteCond %{QUERY_STRING} ^/?announcements/(.*)$

"announcements", etc are not in the query string, they are in the url path.
also, using (.*)$ in this application unnecessary since you aren't using the capture group in your RewriteRule.

RewriteRule ^([A-Za-z0-9]+)$ https://$1.example.com/? [L,R=301]

this is where you should be examining the url path for "announcements", etc.
however, from your examples in the OP i don't see where the "firstnamelastname" exists in the url path so not sure where your subdomain name can be captured from the request.

For firstname lastname I am using wildcard subdomains so it can be any a-z 0-9.

Basically eg.

I want to permanent redirect http://timwillis.example.com/announcements and
http://timwillis.example.com/biography to just

[timwillis.example.com...]