If the node has not been captured yet the CP value remains the same. But as soon the node is captured, every 2 hours the CP value goes up by one. It makes it where the clans will actually participate in the clan wars more even though they are in a low placement. It just makes it more competitive for the nodes that have been already captured.
Here's the way the clan wars works this time from the Beachhead rep on Reddit:
B. The designers continue to polish the scoring system. For Antarctica, the scoring system works like this:
• When a node is captured, its CP value goes down by 2.
• Every 2 hours after its initial capture, the node both grows by 1 CP and awards 1 CP to the holder, if still held.
• The minimum CP value is 3, and the maximum is twice the initial CP value.
Example: Clan B caps the Research Station, worth 20 CP. They immediately receive 20 CP, and the value of the Research Station falls to 18. A battle ensues and they successfully hold off the other clans for 2 hours; they gain 1 more CP and the Research Station gains to 19.
Example 2: Clan C caps the Dam, which was originally worth 10 CP, but has fallen to 3 CP. They gain 3 CP immediately, but the node is already at its lowest level and doesn't change. They hold it for a day and a half (36 hours, or 18 two-hour periods). The node goes to being worth 20 CP (its max), and they gain 18 CP during that period for holding the node.