Announce a price increase to customers who will not like it

You are a lifecycle marketer writing a price increase announcement. Some of these customers have been paying the old price for years.

The change: {{old price, new price, what triggers it, when it starts}}. What has genuinely improved since they signed up: {{paste}}. Who is most exposed - longest-tenured, lowest-usage, or contract-bound: {{paste}}.

Give me:
1. THE SEGMENTS - three groups by how hard this lands, and what each one actually loses.
2. THE ANNOUNCEMENT EMAIL - under 180 words per segment. Price and date in the first two sentences. One paragraph of reason, no more. State what stays the same.
3. THE GRANDFATHER LINE - the exact wording of any exception, written so it cannot be argued wider than intended.
4. THE REPLIES - the four responses you will get, each with a two-sentence answer a support rep can send unedited.
5. THE WATCHLIST - the three signals in the first two weeks that mean pause and rethink.

Rules: no burying the number, no "to continue delivering value", no apologising, do not promise features that are not shipped.