If he wants in, great. If not I'm not gonna be angry. I'm not a fan of bringing in a kid the size of Cam Meredith to play DT.
He has the frame to hold close to 300 with good weight. Juco meal plans are a little different than the Nebraska nutrition he would receive. Weight shouldn't be an issue. He has something Meredith never had. Quick twitch muscles.
If he was a HS recruit, I would be more on your side. Building up to the desired weight in a healthy manner and getting used to playing at the heavier weight generally takes a year to acclimate to, making red shirting linemen almost standard practice. As it is, he is a JUCO and would be counted on right away. His 2nd year could be really good, but I am not sure you would get the immediate impact year 1 which is what you want the player to do as you lose the key development years.