Kind of, yes. It would be interpolated Atmos. The Beam does not have upward firing speakers to do true Atmos channel support, though the Arc does. The One SLs will continue to do the rear surround duty, but for the true side channel support, you would need to replace them with Era 300s. 

So, yes, you’ll be able to “play’ Atmos material using the Beam, but you won’t be getting the full effect. 

@Airgetlam  thanks for the reply much appreciated. 

Yes, you’s get Atmos and the SL’s would be compatible with it, though would not do Atmos themselves.

Be aware the Beam is a much smaller speaker than the Playbar, so you’d miss some bass.

Thanks @106rallye  understand about the beam being smaller just planning for when my playbar decides not to play anymore. Can’t justify/afford the cost of the Arc.