It's hard to argue with the idea that people pushing out low-effort nastygrams will also embrace bots if they prove either reliable enough or cheap enough to proofread; but I suspect that(at least with current likely suspects, it's possible that something less predictable will be unleashed) the effect won't be as dramatic just because of how much business process automation and separation of labor you can already manage, especially when you are just sending scary-looking letters to random little people rather than submitting stuff to a judge who may not appreciate your lack of effort.
The rules frown on purporting to be a lawyer when you are not; but they are substantially more permissive in terms of how thin you can spread your lawyer: even in respectable high end contexts it's quite normal for some, potentially much, of the writing to get farmed out to associates and paralegals unless the fancy partner's expertise is required; and in some sleazy boiler room operation there's not much stopping you from mostly using mail merge and the cheapest clerical temps you can find to turn whatever batches of questionably documented and dubiously collectable debt into letters, with the lawyers there to handle putting the templates together and appearing on the letterhead.
That said, I'd also be skeptical of how far this sort of service could go in redressing fights between significantly unequal parties: especially with things like the dodgy end of consumer collections the real killer isn't necessarily that they have a keen legal mind on the case and you don't(since this is often not true; and such situations are more likely to be disputes of fact rather than some sort of subtle argument); but that they, rather than you, are typically treated as the presumptively respectable party while you are treated as having the burden of disproving the allegation.