"Use the point boys, save the edge for kindling."
Considering the wide use of straight bladed cutlasses over the centuries, there is little doubt thrusting was considered effective. A lot of late sail training pictures and manuals seem to regard what one sees in lots of sabre notes.
Compare George Silver to later traits such as Donald McBane and one still sees undeniable similarities applicable to both straight and curved blades.
There are keggers of discussions re the veracity of cut vs thrust and reviewing those, as well as virtually any treatise on early modern swordsmanship, one can go back to Silver and find a simple truth that "Perfect fight stands upon both blow and thrust, therefore the thrust is not only to be used." However prefaced before that with the statement "That a blow comes continually as near as a thrust, and most commonly nearer, stronger, more swift, and is sooner done."
At any rate, what we see in these photos is quite traditional sabre play but don't forget a long, long tradition of singlestick.