"Do you even still love me?" "Umm..."
"Do you think Jack deserves this promotion?" "Umm..."
"Do you think this software solves the problem?" "Umm..."
"Surely you realise Donald Trump is the true incarnation of the coming messiah?" "Ummmm....."
Those Ummms may well be massive pitfalls. Alternatively, those ummms might accurately indicate that the entire premise of the question is dubious or flat-out false, depending on your delivery.
A person who uses ummm too much may well have severe problems communicating effectively, and a tool to help them only use ummms deliberately and meaningfully might be useful. A person in a presentation may wish to give an air of humility and approachability, in which case the ummms may be helpful - or they may wish to give an air of authority and certainty, in which case that meta-message is shattered by excessive umms.
Intent-based communication is subjectively valid, and one can argue that expecting and requiring perfectly honed communication might be a form of implicit bias and prejudice. I appreciate the idea that, as a societal issue, reducing our dependence on homogenised thought delivery is worth a wider conversation, but I'd say this is the wrong level from which to attack that systemic change. You don't attack scalpel manufacturers for the proliferation of plastic surgery.
Yet one could argue that a communication is - objectively - only as good as the way it is received. And while the majority of your communication might not need that level of certainty, for many people practice is the only thing they require to achieve the appearance of confidence. And democratising the ability to learn that skill doesn't seem to me a bad thing.