It's just up to the installer's assessment of the installation and the likely total load. The charge point manufacturer won't know anything about that, as it's up to the installing electrician to assess the existing installation and ensure that anything he installs doesn't take the load current over that which can be safely handled by the installation.
As mentioned above, it's acceptable to put a peak reading clamp meter on the supply, leave it there for a day or two of normal household operation and use that as the basis for establishing whether or not it's safe to install a 32 A charge point. That's not information that any charge point manufacturer would know, as it varies a great deal from one house to another.
For example, as outlined above, a 60 A supply could be fine with a 32 A charge point for a house that doesn't present high normal loads on the supply. On the other hand, the same 60 A supply would definitely not be OK if the house had an electric shower that was in regular use, as that would probably draw over 40 A all the time it was on.
That all sounds really sensible