More than anything else, the series didn't start downplaying yuri, but drama and heavy themes. The other girl from class, Mophead's "darker" side, pretty much the whole plotline with the girl that is interested in him - it was all part of the more drama-centric/heavy storyline that honestly wouldn't fit the established theme of the manhua. It literary jump from light humor, themes of friendship, goofing with your pals, pursuing love into one of the characters trying to stop himself from raping a drunk girl. Wouldn't be surprised in the slightest, if those got a pretty bad reception from the established reader-base hence the change of direction. The romance plotline after they dropped those themes is fine and doesn't seem toned done all that much. They just jumped over all the planned hurdles, to them being in a constantly happy relationship and everyone else goofing around along the way.
The real problem is that the series is pretty much dropped, not that the author is downplaying yuri.