Can Apple Watch provide blood pressure readings?

No, but the Series 9 and newer can provide hypertension notifications.

...

You can wear Apple Watch to analyze your heart data, which can be used to detect signs of possible hypertension (available on supported models; not available in all countries or regions*).

If your Apple Watch detects patterns of hypertension, you receive a notification to discuss with your healthcare provider. You are also prompted to use a third-party blood pressure cuff to take measurements over a 7-day period. You can set up reminders for the morning and evening.

...

Important: Your Apple Watch is not a medical device and is not intended to replace talking with your doctor for diagnosis, treatment, or monitoring of hypertension. Apple Watch cannot detect a heart attack or identify every instance of hypertension. Hypertension notifications are not intended for use if you have diagnosed hypertension, or are under 22 years old. Hypertension notifications should also not be used during pregnancy.

...

copied from: Receive hypertension notifications on Apple Watch - Apple Support

The Hypertension feature is more for users that do not know they have high blood pressure, as it uses statistical information on weeks to decide if you have hypertension, and then tells you.

If you already know you have High Blood Pressure, the Apple Watch is not going to add any new value.

BobHarris wrote:

If you already know you have High Blood Pressure, the Apple Watch is not going to add any new value.

I can see where it might. I have high blood pressure that is well controlled by medication. When I take my BP, it is normal. But if the meds ever stopped working or working as well, this could give me a warning. So, I turned it on.

IdrisSeabright wrote:

BobHarris wrote:

If you already know you have High Blood Pressure, the Apple Watch is not going to add any new value.

I can see where it might. I have high blood pressure that is well controlled by medication. When I take my BP, it is normal. But if the meds ever stopped working or working as well, this could give me a warning. So, I turned it on.

Good point.