Is there anything wrong with this question? In particular, is there anything wrong in asking about an educated guess about the possible future impact factor of a new journal?
The post in its original form contained the following question:
Moreover, PRResearch is rather new and does not have an impact factor yet. Do you expect the impact factor would be comparable to the PRA/B/C/D/E journals, or to PRL/PRX?
Such a question asks thus for an assessment of a journal, and can be thus considered a shopping question, but since it asks about our expectations on the future impact factor of a journal it can also be considered as opinion based. In both cases, it's not a question we can answer and should be closed as off-topic according to our current policies.
However, the post contains another question that can be answered and the edit from Wrzlprmft removed the unanswarable part, keeping and fixing the answerable one. In this way, the question can be salvaged and kept open.
So, you can essentially choose to have a closed question in its original form or an open question in the edited form.
First of all, a little foreword. I do not think that people who closed my answer have secret agendas, or malicious intentions. But I think that it is enforcing a policy in an extreme strict way, beyond the scope of the rules. I decided to answer my question because all other answers are pinpointing some issues, but not offering a solution. The point is, rules are here for a reason, but they should allow a genuine question to be asked. One should not forget that the first reason of existence this website is to ask questions. If (man-made) laws prevent any meaningful question to be asked, what is the whole point? So, as everybody seem to agree, the original (non meta) question is legitimate, but there is discussion about whether the part about the IF is legitimate or not.
My answer is: The question about the new journal future IF can be formulated in a more general way. It is totally legit to ask about, what are the reasons why an established publishing company is starting a new journal? Does this publishing company have the power to predict, or to manipulate the future importance, impact, broad diffusion (eg., number of readers), reputation, and acceptance in the scientific community?
As a side note: I do not understand why this meta question is downvoted. The meta question is a totally legitimate question and does not violate any of the rules of Acedemia Meta stack exchange, even if there is a debate about whether the original (non meta) question is legitimate.
As a final word. Please be reasonable. Offering or suggesting a way of asking a similar but closely related question in a legitimate way is more welcome than just saying that a question and not legitimate and to close it.