Standardization would allow canal operators to build better and safer tooling around the strait, allowing for more slack and so on.
The alternative is simply to continue as it is, with ship builders squeezing every inch just because they can, and it becomes a matter of if, not when, another EverGiven happens.
Any attempts at standardization would actually be worse, because now they build each ship for exactly one actual canal. With standardization they'd get built to some document that will get interpreted slightly different in every place.