My alt account doesn’t have HoT and I just noticed this.
Non-HoT accounts not only cannot get Guild Shield Gens out of Guild Storage, but they can’t even use them placed in WvW. Further, it doesn’t just not let you on the siege but bugs your character with the shield gen skills. If you watch the video, my character has the shield gen skills after attempting to get on the gen, I have to swap weapons to get normal weapon skills back.
See video demonstration: https://youtu.be/nVOWUEMqjGw
Suggestion: Allow Non-HoT accounts to use new siege placed in open WvW, and allow them to remove WvW siege from storage.