It wouldnt strictly be necessary to implement proper fuzzy logic.
Say the data packet has some internal "quality" modifier, this modifier gets lower every time the data gets retransmitted, or "told" without proper map data transfer.
With lower and lower quality theres an ever increasing chance of soms detail of the data to degrade or change to something false.
Lets say the initial data is
"valuable randomium ore in the north asteroid field of Dethra in the Artash cluster"
With 100% quality.
it gets retransmitted correctly the first time, but its quality gets lowered to 75%
The next time it gets told the data degrades to
"Valuable ore in Dethra in Artash" with quality 50%
"Valuable ore in Arthra ((2 systems over from Dethra)) in Artash" 25% quality
Finally it degrades to "valuable ore in Artash" or maybe even "treasure in Artash".
Maybe we could even ditch the quality stat altogether and just have the data change with every "improper" (hearsay) transmission.
Some data correlation tool would be useful too.
Take all the rumours you think adress the same piece of information and compare them with some highlighting function which marks all the rumours which have coinceding statements.
For example if you mouse over "Artash Cluster" in a rumour all the rumours about Artash and systems in Artash get highlighted, when you click only the marked messages remain in your comparison buffer.
Repeat until only reinforcing statements remain.
Maybe even create a new statement out of all those rumours as "guess" to tell others