They were most certainly aware that technology and human understanding in general were advancing and would continue to advance. From one of Franklin's letters:

The rapid Progress true Science now makes, occasions my Regretting sometimes that I was born so soon. It is impossible to imagine the Height to which may be carried in a 1000 Years the Power of Man over Matter. We may perhaps learn to deprive large Masses of their Gravity & give them absolute Levity, for the sake of easy Transport. Agriculture may diminish its Labour & double its Produce. All Diseases may by sure means be prevented or cured, not excepting even that of Old Age, and our Lives lengthened at pleasure even beyond the antediluvian Standard. O that moral Science were in as fair a Way of Improvement, that Men would cease to be Wolves to one another, and that human Beings would at length learn what they now improperly call Humanity.—

They intentionally designed the patent system to foster this development. They certainly could have predicted that they would also advance. They had seen plenty such advancements in their lifetimes. (Do I need to source this? Seems like common knowledge)

I do not think it seems appropriate to speculate on what they would think of the modern 2A debate in this sub. But it should be noted that there is a process for altering the Constitution via amendments in the event of unforseen issues.