Ok, I should have made that clearer. What I meant was that at least one post on a minor release of Unreal gets to the front page (at least when I'm browsing HN, maybe later or earlier in the day the postings are not on the front page). Out of curiosity I checked my above claim and it was wrong (hehe), but many releases hit the front page:

4.11 - now

4.10 - https://news.ycombinator.com/item?id=10548139 [75 comments]

4.9 - https://news.ycombinator.com/item?id=10147368 [50 comments]

4.8 - https://news.ycombinator.com/item?id=9694885 [98 comments]

4.7 - https://news.ycombinator.com/item?id=9103050 [88 comments]

??? (when they released UE4 for free) - https://news.ycombinator.com/item?id=9132815 [240 comments]

4.0 - https://news.ycombinator.com/item?id=7429774 [163 comments]

But it's probably as you say. Not every interesting post (which also depends on the readers interests, of course) get's to the front page. Coupled with the bigger mindshare of Unreal, and the not so interesting Cryengine releases in the past (especially compared to Unreal) we get more Unreal postings on HN.