Sounds like utter bullshit to me.
That's putting it mildly. As a result of this design stupidity, it sounds to me like anyone who's already leased or built cabinet colocation for their Sierras has to:
1) Build some kind of duct into the side of the cabinets, to mate up firmly to the side of those cases and carry the exhaust heat to the back of the cabinet,
2) If not #1, then at least some apparatus to "block off" the space between the vertical rack rails and the side of the cabinet, and generally vacuum the entire space through a series of fans,
3) Forego most of the real estate on both sides of the vertical rack rails, which would normally be free and clear to tie down cables, and instead only run cabling subordinate to the construction of apparatus 1 or 2 above,
3a) In either scenario, blocking the front of the cabinet with blanking plates, will be key in most datacenter environments. If the boxes sucked at the front and blew at the back, exclusively, then blanking plates would be less of an issue.
4) Ditch the cabinets entirely and switch to 2 or 4-post racks. In leased colo space, this has tremendous implications, as the only way to properly and securely run equipment in those kinds of racks is in a caged space, which probably whacks out the economics of the whole thing. Aside from that, what if a customer had already paid installation NRCs to a datacenter, thinking they'd need xx KW per cabinet, only to find out that Hashfast has pulled the rug out from underneath them with this re-design to 4U, and thus the quantity of power is halved and some of those already-paid monies are wasted.
Further, since there are apparently no engineering drawings of any of this stuff, as DeathForTaxes and others have called for, it's STILL subject to change. For a company that holds themselves out as a group of experts, Hashfast seems to be acting like anything but. It seems to me this could be easily resolved if Hashfast would simply sell what DeathForTaxes is calling "naked" boards. No need to stop selling the all-in-one solutions, vis a vis the Sierras, but don't handcuff the customers who are trying to put food on their tables and yours.