Future of proxy_cache_purge now it's "part of the nginx commercial subscription"?

Take a look at this… http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_cache_purge

Example configuration:

proxy_cache_path /data/nginx/cache keys_zone=cache_zone:10m;

map $request_method $purge_method {
    PURGE   1;
    default 0;

server {
    location / {
        proxy_pass http://backend;
        proxy_cache cache_zone;
        proxy_cache_key $uri;
        proxy_cache_purge $purge_method;

This functionality is available as part of our commercial subscription.

Now, obviously, I’m using nginx-extras which has the functionality in the purge plugin, but it looks like nginx have “baked this in” to the core commercial offering. Do you think our purging system is safe, or will they try and remove it/block the plugin?

Incidentally, commercial subscriptions “start at $1,350 per annum”… yikes!