The team states that the difficult to do so was difficult and was approached with considerable thought. The ultimate culprit for this decision was dwindling player count it seems,
“But ultimately, the game’s population levels have decreased and reached a level where the original experience we hoped for and envisioned for Rend is no longer a possibility. We will formally shut down all public servers on Friday 1/31. While today’s news is a disappointment, we’re sincerely grateful to our players, partners and the community for your commitment and support. Thank you for joining us on the battlefield.”
With this news, you can still continuing playing Rend until January 31, but it will no longer be on sale on Steam. Forums will be shut down shortly after the servers are shut down. After January 31, you won’t be able to play Rend on public, nor will Frostkeep offer any support or interference for private servers.