Historically, they've been refreshed every year to every eighteen months. The last releases have been in March, 2020 (last Intel release), November 2020 (M1), and June 2022 (M2). I personally expect the 13 with M3 to be released either as part of the first batch of M3 Macs this fall (along with the 13-inch MacBook Pro, 24-inch iMac, and potentially the Mac mini), or as part of a second release in early 2024 (including the 14- and 16-inch MacBook Pros, and potentially the Mac mini). If your current machine can serve your needs until October or November, I'd wait until then. Elsewise, the M2 on a discount is a capable machine (even though I prefer a 16/512 config).