The weights are part of the model, not the algorithm. Whether these can be copyrighted is (a) unclear and (b) should have no bearing on the status of the algorithm itself.

Edit: The output of an algorithm has been ruled by courts to not be copyrightable. A Transformer is, itself, the "output" of an algorithm (e.g., SGD). Therefore, IMHO (IANAL), a Transformer cannot be copyrighted. We'll see if the judges who start taking these cases are savvy enough to rule correctly. Similarly, recipes cannot be copyrighted and they're quite similar to algorithms.