Shape of space simply means the "Metric Tensor", and saying it's the sum total of what General Relativity is describing isn't some "bold" or "weird" framing (your words); it's both complete and correct.
It isn't so simple, even in GR:
https://plato.stanford.edu/entries/spacetime-holearg/
It isn't so simple, even in GR:
https://plato.stanford.edu/entries/spacetime-holearg/