RKN would be rare if you haven't had problems with them before and if you do have them then they are already throughout your soil so problems should be seen in other plants as well. Sacrificing one plant won't prevent further contamination but it is the only way you can confirm them. So if you wish you can pull up one plant and check for the root galls.

But there are many possible reasons for wilts with tomatoes and stem knots on tomato stems are often nothing more than normal primordia.

But to be sure we'd need some additional info or a photo if at all possible.

Dave

You wrote:
"The stems are getting filled with light colored knots that I believe to be Root Knot Nematodes.

Not so. As was said, RKN affects roots, not stems.

Also as said, the bumps on your stems are root initials. So, stop worrying about the bumps.

I won't worry about the infected plants,they got pitched.

Too bad. You didn't have to do that.