You could always harvest lava from brand new Schylling Lava Lamps. If you have a small amount of MT Goo, it can be mixed with Schylling brand lava.
I'm guessing MT is handling other business affairs and accepting new orders for their goo may not be their top priority at this time---considering the costs to run a business. I imagine their giant lava lamp sales might be the majority of their revenue, but I could be wrong.
Glad I stocked up a few months before their announcement.
There are pages and other posts here on OG about making your own goo from Paraffin wax, Mineral Oil, and Brakleen if you're feeling adventurous.
They haven't made a large lava lamp in years
Their Die-Cast business is talking precedent for their revenue stream
In addition, their resources for raw materials is not providing consistent quality/specs
As a result, they are tearing down the area committed to blending waxes and utilizing it for Die-Cast