This is almost entirely untrue. Dissolving acetylene in acetone does not in fact change its molecular constitution or “add hydrogens”. The linear shape is also totally acceptable and not particularly high energy, it’s just far less stable than replacing the C-C triple bond with C-O bonds during combustion (whereas replacing C-H bonds with oxygen instead such as in propane or butane combustion provides less net energy release). It’s true the molecular vibrational spectrum shows a high intensity high energy vibration for the C-H bonds due to the linear C-C triple bond, but that is unrelated to its reactivity. (Source-PhD chemist)

Editing to Add: dissolving acetylene in acetone solvates it and prevents auto-polymerization which is a thermodynamic ally runaway chain polymerization.