Very interesting. I have heard some people think that some manufactures may have a bunch of these sitting around (made a long time ago). They may have decided to re-stamp them and sell them with a new date.
With that said, It sure looks from the link that someone made a new batch of them.
I think this is good news, as at one time people were thinking that these chips would get hard to find and expensive.
I have used Russain K1551D chips marked much older in some of my clocks. Never had a problem with them.
I bought a small batch of them as well and they cost about a third of what they usually cost. I wanted to build my first clock with them but i am having problems. I think i broke some of them by accident but im not sure if that was actually my fault or if the quality is just bad. At the beginning they worked fine but at the moment some of them are lighting up more than one digit at once and if i count up from 0 to 9 there are most of the time 2-3 digits glowing. I got 5-6 broken ones and the same amount on working ones. The last one broke when i accidently touched two pins at once with a clamp of my multimeter. Maybe the voltage is to high or something. im using 14k resistances in front of the nixies and the voltage from the power supply without load is 189V.
I had something like this as well: Please check the number on them carefully and that they are marked K155ID1, and not K551 or something else. Russian chip numbering is not something that I understand very well, and to me it seems very confusing, and it is very easy to mix up totally different chips.
The K155ID1 is suitable for driving Nixies, but the other one doesn't have the voltage capability. However the wrong ones are much cheaper and don't have the voltage rating... They are not fake, they are just a totally different part.
Many interesting and useful chips which has no equivalent elsewhere.
My favourite being K176IE12. With a 32kHz crystal it has pulse outputs for 1 Hz (seconds), 2 Hz (hour/min separator lamp) and 1/60 Hz (minutes). Useful if you don't work with microcontrollers...