if you don't know what an SRE is, you're not the intended audience. probably half of the articles posted to HN are unintelligible to non-practitioners of that particular subfield, don't see why this should be different.
1. it's a hinderence for people who are studying to become the intended audience.
2. sometimes I'm reading two literatures that use the same acronym, so it's momentarily stupifying.
It really helps when HN posters either clarify things a bit in the title, or if that's not practical, make a comment when you post the link.
[2] I know, ABBR is the new hotness, but I'm still using HTML 4 for my blog and old habits die hard.