No, your existing subscribers will not receive any notification from Apple.
You have chosen the "grandfathering" option. The entire notification and consent system is built around getting a user's permission to charge them more money. Since your existing users' price is not changing, there is no need for consent, and therefore Apple will not send them any emails or push notifications about the price change.
Here's a breakdown of what happens and why, based on my experience and Apple's system design:
The Key Principle is Consent: The entire reason for Apple's price increase notifications (the emails, push notifications, and the in-app consent sheet) is to comply with consumer protection laws and App Store rules. A company cannot start charging a user a higher recurring fee without their explicit consent.
Your Chosen Path Bypasses the Need for Consent: By selecting "Keep the current price for existing subscribers," you are telling Apple:
For User A, who subscribed at $9.99/year, continue charging them $9.99/year forever (or until they cancel).
There is no change to the financial agreement with User A, so their consent is not required.
Therefore, there is no trigger for Apple's notification system for User A.
Who Sees What?
Existing, Active Subscribers: They will see nothing. Their subscription will continue to auto-renew at their original, lower price. From their perspective, nothing has changed. This is exactly the "no confusion" outcome you want.
New Subscribers: Anyone who subscribes after your price change goes into effect will only see and be charged the new, higher price.
Lapsed Subscribers: This is an important edge case. If a user's subscription at the old price expires (e.g., due to a billing issue they don't resolve, or they cancel) and they decide to re-subscribe after the price change is live, they will be treated as a new subscriber. They will have to pay the new, higher price.
For Contrast: What Happens if You Choose the Other Option
To give you peace of mind that you've chosen the right path, here is what happens if you choose the other option, "Increase the price for existing subscribers":
Apple sends notifications: Apple sends an email and a push notification to every affected subscriber, informing them of the upcoming price increase.
In-App Consent is Required: The next time the user opens your app, the OS will automatically present a "Price Consent Sheet" (a system-level pop-up) asking them to agree to the new price.
The Risk: If a user does not see or does not agree to the new price before their next renewal date, their subscription will automatically expire. This is a significant risk and is the main reason most developers choose the grandfathering option unless they have a very compelling reason to force a price increase on everyone.