I've never written reviews much. I did when I first entered the hobby 5 or so years ago, but I quickly stopped. Most of those I choose to see are well reviewed. I wouldn't be adding anything except an update confirming the other reviews. I did write reviews initially, but since them I've only written reviews when I saw someone who only had a handful of reviews total, or one or two situations where I thought I was adding some additional insight.
Not writing reviews for me had nothing to do with anything legal, and I'm still not really concerned about reviews in that regard for various reasons. So I'd be comfortable writing a review if I saw someone who didn't have any for a couple of months just to say "saw her recently and she still looks like her photos, and I had a great time". I just didn't do that before because other people were. Or I'd do it if I were asked to write a review by the girl herself.
As for reviews and their impact on whether or not I see someone --- Reviews give me an idea of what to expect in regard to both appearance, performance, and personality.
If someone has a lot of reviews, and then suddenly none for a while, I wonder if they took time away. I can usually sort of figure out if that's likely or not by searching ad postings, schedules, etc. And I have a good handle on which ladies are active in the area, whether they're mostly local, travel here frequently, travel here once in a while, or haven't really been here before. Even if I'm not really interested in seeing them, I know who they are. And I know who is around and available even if I'm not looking to see anyone for a while. So it usually doesn't take much effort to figure out if she has been active and just doesn't have a recent review compared to having not been active for some time.
Depending on the length of time, I may worry about how accurate the photos are. But if she has a gallery with dated albums and it's clear that there is an album from that ("reviewless") time frame, I can use the old reviews to some extent. If the older reviews suggest that the older photos are the girl and are a good representation, I can sort of go from "Ok, she is the girl in the old photos and they were a good representation of her. And these new photos appear to be that same person in the old photos... OK, I'm fairly confident I know what I'm getting physically (whether there is change or not to her figure/weight)".
The other thing that can change over time is performance. If all of the old reviews are very good, not having a review in the past couple of months won't sway me much as long as I can confirm appearance like I mentioned above. If they had hit and miss reviews, I'd probably wait for a review to pop up before moving any further.
If I'm interested based on past reviews and photos but she doesn't have recent photos posted, then I'm a little skeptical. In that situation, I may contact her and ask if she has current photos. I've done this and have gotten "in the gallery on my site" (which were photos that I knew were old) and I've also been sent some photos. Not having any won't 100% rule it out, but providing some photos goes A LONG way. Even if she just snapped a couple with her cell phone and sent them via email. They don't need to be provocative or anything. I just want to have an idea of what her figure looks like and how it compares to the older photos.
So my suggestion would be post updated photos regularly and date the albums. They don't always need to be professional. I think I speak for many when I say that we often prefer regular photos because that's more of what we'll get (no air brushing, unnatural lighting which makes the photo look great but isn't realistic, etc.). Don't get me wrong, I love a good professional set as well. But the intent is more to say "hey, this is how I look these days". And if I know you regularly update your photos, a lack of recent reviews is not a big deal if the recent pics are good and the older reviews are good.