New hardware announcements during a WWDC keynote are rare but not unheard of. Apple cunningly snuck in reveals of updated iMac and iPad Pro models in WWDC 2017, the then-new Mac Pro in 2019, and announced its Mac line-up transition to Apple Silicon chips in 2020.
On that regard, there have been plenty of rumours suggesting new Apple hardware that are planned to be unveiled this year. These range from redesigned iPad mini and MacBook Pro, a VR/AR/mixed reality headset, to the ever elusive Air Tags. Most of which were tipped to be revealed during a supposed “surprise” keynote on 23 March, which never happened.
As to whether Apple will announce a new piece of hardware remains to be seen. Regardless, we’ll eventually find out when WWDC 2021 kicks off in another two months time.