The truth is, we simply don't know, none of us do. We can't really get inside your wife's mind, and we don't have any special insight regarding her mind, we only have our own experience.
Trickle truth, possibly, possibly not, most of us have dealt with that, and it gives us a very negative feedback loop about slow and progressive disclosures.
Also, my wife told me once that a contractor subtly hit on her but she disclosed it to me years after.
This experience mirrors, one of mine, it was a family "friend" who hit on my wife, she did not disclose it at the time, our children were friends, my wife did not disclose this until after she had confessed to her affair because she didn't want cause any circumstance change to family and children activities. She was not interested, but it forcefully brought back to her mind her previous affair which she had successfully concealed from me, and which she had been tightly compartmentalizing since.
This occurred several years after her affair, but her disclosure occurred during counseling after her disclosure of the affair. Had she informed me, our children would not have seen their children, and we would not have had anything to do with them again. Once she reported it, during counseling, or contact with them end it. He died recently, someone contacted us to let us know that they were having a "memorial". Needless to say, I will not be attending nor will my spouse.
On the other hand, this happened to me, I would've reported it immediately to my spouse, and I have when it occurred.
When it came to my wife's affair, the guy that started hitting on her, and she reciprocated, or potentially she may have actually started hitting on him initially, and he reciprocated, it's not really clear. She not only didn't tell me, she kept it secret, then engaged in the affair, then kept that semi-secret, making sure nobody let me know, and when I became disturbed by her behavior only confessed at the time to him acting interested, denied having any involvement, interest, or otherwise.
Yet, she was already serving up the full menu, so to speak, and the trickle truth continued for 9+ years, through a multimonth session with one MC around the time of the affair, then 9 years later with the second separate MC, where she not only confessed to the physical affair, but told an entirely false story of their sexual encounters!
Then, the true confession 6+ months later! The true confession sexual part wasn't worse than the initial one, so it really didn't make any sense, but she said that she couldn't bring herself to actually "tell the true story, but she could tell a false story".
So keep that in mind. Your wife may have actually told you everything there is to tell. Or, she might've told you nothing about what she has to tell you that you really want/need to know. We have no way of knowing.
As the song says, "people are crazy".