It is all true if you really believe that the particular chip really implements the AB.
On the other hand is it possible to write a firmware that drives the regular non-AB mining chips in such a way that they appear to produce results that look like made with the AB.
Regarding BM's AB, everything I'd read is/was saying that it was a hardware implementation in the chips but able to be switched on/off. Considering it was never put to use, the ability to simulate (fake) AB by reprogramming the FPGA makes more sense as oppose to wasting die space on unused circuitry.
Intel's patent application definitely is a hardware implementation probably destined to become a Foundry IP block for use by whoever wants to pay the royalty.
As for Halong's 'open' version...
A) To me it is a blatant attempt to hijack other mfgr's IP by saying, "Sure. You can use our 1 patent for 'free' -- provided you open access to all of your IP and lift all vendor NDA's as well.
B) Their miners only work with a pool that implements the stratum AB switches. While writing/testing the T1's driver -ck has been emphatic on that. When he forced the firmware to connect to a non-AB pool only 1/4 of the hash's produced are valid. Now if they manage to convince most of the pools to support the new stratum code to use AB then yes the Halongitosis patent does become a rather large carrot to dangle even if it is a very malodorous one-- assuming the T1 miners eventually live up to their promised specs. So far the jury remains out on that point.
C) My feeling is that not only Intel but also Bitmain, Canaan, Bitfury et al will all pursue their own implementation of covert AB. Hell, with Samsung getting into the ASIC miner chip biz it would even make sense for them to also come up with a Foundry IP block for AB to drop into whoever wants it in their chips.