In this paper, we consider an CSMA/CA network supporting multi-node transmissions. To meet the timeliness and reliability, the communications are operated with finite blocklength (FBL) codes and truncated hybrid automatic repeat request (HARQ) scheme. We characterize the timeliness of packets utilized for decision-making via Age upon Decisions (AuD) in such unsaturated CSMA/CA wireless networks under truncated HARQ protocol. In particular, we develop an equivalent unsaturated Markov transfer model according to the considered network and calculate the value of transmission probability and collision probability, respectively. Then, we introduce a method to calculate the average AuD with Bernoulli decision process and obtain a closed-form expression following these characterizations. Via simulations, the performance of the considered network is evaluated and we conclude a series of design guidelines.