I don’t know how Sentai aka TAN feels about this but, Rightstufanime.com sells your products way before the street date. Knights of Sidonia 2 is available for sale a whopping 3 1/2 weeks before street date. That’s just the tip of the iceberg. All Sentai titles are made available to the general public about a month in advance of the street date. They don’t even try to hide it. They list it as in stock while conflicting with the their posted release date. No other retailer is allowed to do this. What makes Rightsuf so special?
As Far As I Know, RightStuf puts items on sale once they receive them, unless the manufacturer specifically asks them to hold those items for the “release date”. They’ve done this with Sentai’s releases as well as some from others, I don’t think Sentai has any problem with them doing so. Other retailers may have other policies.
Also take into account that Right Stuf always ships early if you have an item on pre-order, basically as soon as the item is in their warehouse.