That doesn't seem to be the case anymore. I tried ViaBTC to include a transaction of 5KB for someone that was desperate to get it confirmed, but they kept refusing it stating that their limit was reached.

That while the transaction included a fee of 0.0003BTC/KB. Even with them having found a few blocks quickly after each other they didn't let it through, and that while sub 1KB transactions were accepted directly.

It seems that their willingness to help out the community has decreased, and for that reason ignore heavy transactions, or we have been unlucky, which I doubt since smaller weight transactions were accepted each time.