The group-mentions ack gate returned false whenever a group did not require mentions, conflating group policy with whether this message mentioned the agent. Under the default scope, mentioning the agent in a group configured to answer everything produced no ack at all, so the user had no signal the turn was picked up until the reply arrived.
Behavior change on a default path: those groups now show the 👀 ack (and the lifecycle status reactions when messages.statusReactions.enabled is true) on mentions. Mention-required groups, group-all, unmentioned messages, and off/none are unchanged. The gate no longer reads requireMention, so the parameter is gone from the shared type and all channel call sites.
Proven live on Telegram across three configurations, including a no-mention control confirming group-mentions did not become group-all.
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