Yes it's a bit suspicious because they contradict themselves on the same page, at the top they say
"Rest assured, your personal information will not be shared" and at the bottom they say
"Do not include any personal information, such as your name, email address, and contact details" 
!!!
As you said, everyone understands “personal information” to mean information such as phone numbers, email addresses, or names!!!
Frankly, I don't know. Either they are lying or they do not know what they are saying because this is a clear contradiction.
I haven't submitted any review using the site yet, but If I understand well, I think they discourage people from including their personal detail in the review description area. Now, once someone proceeds by submitting the review, they will be asked to enter their phone number or email address to "curb" spam. Maybe that's what they meant based on stafstor's findings.