This site is doubling down and says we are - still pretty much a rumor at this point till ABC says so

https://movietvtechgeeks.com/agents-of-shield-devils-complex-earns-marvels-show-season-6

UPDATE: 4-5-2018 6:30 PM ET: We’ve now had the news of Agents of SHIELD being renewed for season 6 confirmed by three sources at ABC, Disney and the production team letting us know the show will go on.

Agents of SHIELD deserves a season 6. Fantastic writing in the past three episodes shouldn’t go to waste. Before we go on, for those who haven’t caught up, this is a SPOILER ALERT. You can come back later. If you are, let’s revel in how great SHIELD has been lately. It’s just sad we have to discuss life support every season since season 3. My initial view of the season’s first arc really felt dark and stifling, but ever since the team came home from the future, things seemed to perk up. I’ve been having a pretty busy life lately not having been able to discuss this show since episode 99.

Agents of SHIELD Season 6 News: Jed Whedon and Maurissa Tancharoen told TV Line that they were ready for Season 5 to be the end of the line for SHIELD, but ABC has other plans for them with a Season 6 renewal. Our friends at the network let us know that it’s not over yet, and a move back to Tuesday night might be coming.

Many have been predicting the end of the show due to its low numbers, but Agents of SHIELD is one people DVR and watch over the weekend. Like CW’s Supernatural, SHIELD has a very loyal stable audience which counts for a lot with Marvel. Plus that Marvel, Disney and ABC connection is powerful, and with the new Avengers: Infinity War film about to hit, you can bet a killer weekend box office number will help push their decision.

“Disney doesn’t want to lose another Avengers connection on network television,” out ABC source said. “With the upcoming season 5 finale coming in May, expect a season 6 announcement which should give diehard fans some good news.”