I think I'm going to start avoiding "Yuri" where the women aren't incredibly upfront about wanting to date the other woman. That seems to be the biggest "tell" for Yuri bait nowadays, is everything is just "subtext" and "you're important to me" and using extremely ambiguous "I like you" with an unsaid "(as a friend)". If they're aren't upfront about wanting to date, kiss, or bone other women, then it's probably bait. By this criteria, it's not looking good for "The Guy She Was Interested in Wasn't a Guy at All".
Just pointing out for everyone else's sake: this is a really blunt method that would filter out some of the most interesting and popular yuri series releasing today. Some examples:
Sci-fi novel series 'Twinstar Cyclone Runaway' introduces the potential for romance in an oblique way: through a pair activity only a husband and wife is supposed to do (fishing in space), in a far future setting where same-sex marriage is an unknown concept. Horror series 'Normality and Monsters' and 'A Monster Wants to Eat Me' where the overt expression of desire is cannibalism at first. The protagonist of 'The Fed Up Office Lady Wants to Serve the Villainess' still doesn't know that she is in the middle of a love triangle, and her love interests are not fully explicit about their feelings. In the supernatural drama 'Love Bullet' the protagonist cannot fall in love until she gets resurrected. In the bloody violent 'Sugar Girl Drip' two girls help each other heal after surviving an awful situation, but have yet to admit their feelings to themselves.
Then there are some excellent ongoing series that are now 100% locked in for lesbian romance but would not have passed this filter of being upfront when they started out. The protagonist of 'The Moon on a Rainy Night' took the whole first volume to admit to herself that she's gay (also a roundabout way), while the protagonist of 'Otherside Picnic' took more than a full volume of the novel to realize what her partner meant by kissing her hand and saying "I love you". The beloved 'Girl Friends' series from the 2000s also started with clueless leads who took a while until they could be honest about what they wanted.
Disavowal and denial of non-heterosexual desire -at least initially- is a very common theme of queer romance, and yuri leads are frequently inexperienced and unaware of their sexual orientation, so they often need a while to be honest with themselves. This is why recognizing an intentional yuri narrative often takes at least a bit of patience, familiarity with tropes, and willingness to connect dots. The presence of the yuri tag on official sources is also a reliable indicator of yuri most of the time, which is why I'm not at all worried about the green yuri ending like this one did. (I have read a lot of yuri and I could count on one hand the series with a truly pointless ending.)