Currently the official "Zabbix server health" template has a trigger prototype:

Proxy [

{#PROXY.NAME}]: Zabbix proxy is incompatible
last(/Zabbix server/zabbix.proxy.compatibility[{#PROXY.NAME}

],#1)<>1

However, there are two separate levels of proxy incompatibility:

Unsupported (3): Proxy version is not supported by server version 6.4.x
Outdated(2): Proxy version is outdated, only data collection and remote execution is available with server version 6.4.x

While both situations must be fixed, unsupported is much worse than outdated.
I think they may have separate triggers with different descriptions and severities.