I could see that if such the rule was "within 100 yards of a forest" or something, but that would only cover a tiny fraction of the city.
In California that is defined as the “Wildland/Urban Interface”. That zone has been subject to much stricter building codes since 2008. Timber frame homes are allowed, as other factors (venting, roof material, rain gutters, roof material, siding material, landscaping) are dramatically more important.
The vast majority or LA county homes are not in a WUI zone, so wildfire extent can’t be used as an argument for this.
Los Angeles isn’t seeing massive fires on an annual basis - at least, not the parts of LA that would be affected by this.