I don't see anything urgent here. The pages in question are 2/3 of the
domain and there are active sysops: if you're in a hurry, you'd better
start a discussion locally now rather than later, your last discussion
edit was in 2009.
When local attempts fail, historically those who believe the subdomain
is currently inhabitable have several options:
* live and let live: simply ask hospitality on incubator or nl.books,
non-standard but equally valid homes;
* community awakening: propose action at the local village pump and ask
the nl.wiki community to join the discussion;
* nuclear option (not recommended): ask closure of the subdomain
(typically involves ForestFire across all village pumps, Wikimedia
Forum, mailing lists and RfC).
None of these involves wikitech-ambassadors.
Nemo