I strongly disagree. As someone who's been following news of Kimja very closely, I believe that Anne had already made her decision in pairing up Kim and James for Samee Ngern Phon even without encouragement from fans. I say that because Ch. 3 promoted them at their calendar event. Before that, no one even knew that Kim and James were going to pair up. It was only after the promotion and seeing them together that fans were so hyped and flooded Anne's IG with requests. Even then, I believe that it didn't help Anne in finalizing her decision to pair them up, but rather it had convinced her that she had made the right decision...and it was simply an encouragement to her. Why else would Ch. 3 promote Kim and James at their calendar event if it weren't for the fact that they were already in the process of pairing them up and they wanted to prepare fans for their upcoming lakorn?
I don't understand what you mean by Anne not having a choice in pairing Kim and James up. If she had a choice to not pair up Mark and Kim in here, yet she still choose to...then she also had a choice to either pair up or not pair up Kim and James in Samee Ngern Phon. And in the end, she did choose to pair them up. I believe her decision was based more so on suitability of the characters. I do believe, however, that she paired them up in hopes of them becoming a popular onscreen couple too.
I think in today's world no actor or actress can be successful without at least being a little popular. As I said, I do believe Anne casts Kim in her lakorns based on her popularity also, but I believe it's more so based on her acting ability. There are a lot of popular actresses in this generation (one or two who are even more popular than Kim right now, such as Yaya), but Anne chooses to promote Kim. That means she sees Kim as the one having the most potential and the one with the most talent. Kim isn't only recognized for her pairing with Mark either. I, along with many others, admire Kim individually and for her acting talent. It's true that nowadays there are a lot of fans who only follow daras based on their koo jin work. However, there are still a handful of others who follow actors and actresses for their acting skills.