The description in the instructions is slightly ambiguous and not clear in its context. The last sentence can be taken to mean different things.
Although I do not have experience with this turntable the instructions may indicate that the contacts supplying power to the bridge rails have a break, rather than being continuous for the full 360 degrees. This interpretation appears to be similar to that of the Walthers 933-2849 turntable. See 09330000002849.pdf
which has a photo of this contact area on page 4.
In this case the polarity does not remain constant as the turntable passes through 180 degrees. There are likely to be breaks on opposite sides of the turntable circular contacts. If you can lift the bridge from its base the breaks in the contact strips will be readily apparent, and will be located about 180 degrees apart. The bridge rails will have no power as the bridge contacts pass over this dead area. Once past the dead area the bridge rails will be of a polarity consistent with the starting polarity.
One problem with this arrangement is that the loco chip will shut down as it passes over the dead section. I don't know what effect a stay alive will have in this situation.
A frog juicer or auto reversing component is not necessary or advisable in this situation.
If however the turntable has continuous contact strips (such as a vertical RCA plug) the bridge rails will have a constant polarity which will cause a short after a 180 degrees turn as a loco leaves the turntable and contacts an approach track.
In this situation a frog juicer or auto reversing component is very desirable for the circuit supplying power to the bridge deck. The only alternative is a manual (and risky) reversing switch.
You can check the table rail polarity in situ using a simple multimeter or voltmeter on DC but not DCC. Check it at various locations throughout the 360 degrees rotation. Temporarily supply DC from a battery or simple low voltage transformer with a DC output.