I agree it changes the experience of playing the game for a human quite a bit, and you'll use different tactics, but for the kind of solver I made it doesn't change much - I had to change very little code to make it work.

From the perspective of the solver it just means the starting set of potential solutions is every word in the dictionary, instead of every permutation, but it doesn't really make much of a structural difference. Either way a solver can just brute-force its way through every potential solution since there aren't that many.

The other difference is that Mastermind tells you only how many of the pegs are correct, but not which ones. Wordle tells you which ones. That is easier, but it's counterbalanced by Wordle having a larger solution space. There's only 1296 possible solutions for classic Mastermind (4 pegs, 6 colors).