Is this true that hydrofluoric acid evolves out of Macor (a type of ceramic) when it is heated in a vacuum? References please in support.?

Here is an extract from this link:

http://www.substrateheating.com/High%20temp%20mate...

Macor - is a machinable glass ceramic and easily machined with conventional metal working tools. It is an ideal prototyping material for use in a vacuum environment at low or high temperature. Continuous use temperature is 800 C with short exposure up to 1000C, and the coefficient of thermal expansion matches most metals. Macor has zero porosity, a very low thermal conductivity and good electrical insulation properties, and so is ideal for in vacuum heater isolators and supports. It does however have poor resistance to thermal shock.

From this it seems that it does not evolve HF.