I could be wrong for sure BUT what I think he means is HOW the last update played out wasn't the type of NTS he prefers. Some only like NTS when the MC is present or actively participating. The wife leaving her phone and leaving it up to MC/reader to guess and assume she's just going to be faithful. I mention this as I someone who enjoys when the MC doesn't know for sure what's going on, and has to rely on the trust he has with his partner. It adds to the thrill, but other NTS fan may not like that. For them it's too close to NTR. For another example, the last scene.
Wasn't an issue for me though.