we are working on organizing everything as best we can when we opened up the group buy our mail system was bombarded with questions and orders and became nearly impossible to sort everything out. We are even still being bombarded with mail. We are a small team at itop and doing our best to help this community. we had to also put up a lot of our money to make such big orders and then it took time to exchange BTC and ETH that was used to fill many orders in a downtrend market. We have been in constant communication with Baikal trying to get another order but at this time are unable. Our goal for this group buy was to offer these units at the best prices we can and build a solid reputation for our company. We however cannot please everyone but we will continue to try to be the best option for this community. I will keep you all updated as we move forward but at this time refrain from emailing I will respond on here as everyone who has the same questions can be answered together. 

It seems they are not keeping a list of people interested in the next batch.

Just keep an eye on the forum and their website i guess, I also wrote a mail for batch 1 and was not even lucky to get in batch 2 where extra positions got open again at a certain time.
They were not filled with people waiting but were filled with people responding at the moment of writing here on the forum.

Correct me if i am wrong Blockhunter, this is what I experienced.

Happy Mining everyone !

PS: if you do keep a list Blockhunter please check if I am on it