Based on my research electronic meters (such as one of those I mentioned) work by sensing a magnetic pulse every time the internal impeller rotates. Assuming that they do actually sense the pulse then they will be as accurate as a mechanical meter.
That just leaves the radio transmission of the stored data, which these days is virtually foolproof, with various types of error detection and correction.
They are mostly designed to be read once a year and generally work by having a “read date” stored in them when they are initialised. They accumulate the data from that date until the same date the following year. The stored data is then read on or after that date.
The local water authority is unlikely to do such readings. It would be up to the Owners Corporation.
Note that installation of the meters need not be optional. The incoming water pipe and tap is common property. The OC is completely within its rights to mandate the installation of such a meter by way of a Special Resolution, under Sect. 65A of the Act.
The only possible problem would be that an owner could remove the meter and install a tap for part of the year. In the case of radio meters it would be easy to detect via regular checks, which would reveal that the reading had not changed over a period of time. They may also have built-in tamper detection.