Yes, it is an ad. I am very tempted to delete it because it is spam, as well as dishonest.
However, I am tempted to leave it, with the warning that it is bullshit and basically a scam based on scaremongering.
Printing with ABS can produce low-levels of HCN, but during normal printing the levels are well below safe limits. If you have a well-ventilated room, it should not be a problem. If you have an enclosed space or no circulation it is a good idea to get some ventilation, you may want to do this anyway because the fumes can be unpleasant even if not toxic.
There are background levels of HCN in the environment anyway, and these are not dangerous. HCN is toxic because it prevents transport of oxygen. In general the effects of HCN go away when exposure to the gas is removed, there are no significant cumulative effects at the trace levels emitted by printers.
ABS plastics do emit significant levels of HCN if they are burnt, so this should definitely be avoided. If you have some ABS catch fire, ventilate the area and leave it for a while.
PLA does not emit any HCN. Other plastics like Nylon may emit more HCN, and I would advise caution if using those polymers.