In the timeline, it is three days between those two episodes. I assume Rick told his closest members about Negan, plus Carol and Morgan are still unaccounted for by the group. Father Gabriel most likely was covering all the bases of what might to expect when the Saviors showed up.

"I have this Nightmare. I'm on 5th avenue watching the St. Patrick's Day parade and I have a coronary and nine thousand cops march happily over my body." Chief Sidney Green