I've never heard of any inspirational connection between the two. More likely
Thundercats
is a response to the massive success of
Masters of the Universe
. There were a lot of
MOTU
clones in its aftermath and
Thundercats
just happened to be the most successful one, carving out its own niche and surpassing
MOTU
artistically as a series IMO. Anthropomorphizing cats was just a way (a brilliant one it turned out) to help differentiate the two.

A journey into the realm of the obscure:
http://saturdayshowcase.blogspot.com/