There may be something to it. Grinding steel is a pretty nasty process. At the microscopic level you are plowing up ductile material with a cutting tool that may have up to a 70 to 80 degree negative rake and never less than about a 20 degree negative rake and it generates a great deal of localized heating at the grind interface. Tru turning with a tool having a 45 degree negative rake to appreciate the plowing of the surface and the amount of heat generated.
When you grind you end up with two things at the surface. Really high residual stresses and metal that has been raised above the austenite temperature and then very quickly quenched to the tool temperature. The high residual stresses will relieve themselves over time and the rapidly quenched material in high speed steel will have a high likelyhood of having retained austenite which will convert to martensite over several hours. Cryogenic treatment will force retained austenite to convert to martensite almost immediately. I am aware of heat treated high speed steel tools that blew up after several hours when not placed immediately into tempering after the quench due to the conversion of austenite to martensite.
Something similar happens in iron castings left for several years to "age". The residual stresses relieve themselves over time and the iron casting becomes more stable.
I would expect little difference between a freshly ground tool and an aged tool if the honing process was done on all ground surfaces with enough material removed to eliminate the heated metal and all of the residually stressed material. I don't know anyone who hones a tool enough to accomplish the materal removal.