No, it doesn't mean that, because the Lee Enfield rifle is not subject to any magazine restrictions. No rifle is. The wording of the law makes the magazines themselves prohibited items if they meet certain criteria. If a magazine is made for a semi-auto (or worse) centre-fire long gun that magazine will be restricted to five rounds capacity. If it is not made for a semi-auto it can hold more than five rounds and not be prohibited. The ten round magazine of the Lee Enfield could have been subject to those restrictions because it is also the magazine for a Charlton conversion of the Lee Enfield, but the exemption was written in to make it clear that Lee Enfield magazines won't be treated as though they are Charlton magazines.
This is why magazines made for something else with a capacity greater than five rounds can be used legally in your semi-auto centre fire long gun while magazines made for a semi-auto centrefire long gun and having a capacity of more than five rounds are prohibited even if you don't have the gun to use theme in. The regulation is about the magazines, not the guns.
Magazines for the AIA bolt-action rifles won't be treated as prohibited ten round magazines for M14 rifles and the Chinese copies of M14 rifles because they are magazines for a bolt action rifle. If you had a magazines for an M14 not pinned to hold fewer than six rounds would be illegal to use in a bolt-action like the AIA because it would be illegal to possess in any case.