Yes. Using the mobile app or website to check in is effectively the same as being offered points and accepting them, but then having the option to change that on arrival. I believe the app/website even notes this during the check-in process. According to https://help.marriott.com/s/article/Article-22358 :

"When checking-in on the Marriott Bonvoy® Mobile App or through our website, the choice for the Arrival Gift (otherwise known as Welcome Gift) will default to Marriott Bonvoy® Points. Should you wish to change to another option, please speak with the Front Desk upon arrival."

If a guest who used mobile check-in wants a different Welcome Gift (choices vary by brand and geography), then It's the guest's responsibility bring up the subject at check-in.

HOWEVER...

Jacksonville Downtown Marriott is branded as a Marriott Hotels property. For the Marriott Hotels brand, Guaranteed Lounge Access is a separate benefit with its own guarantee: "Globally: U.S. $100 If no continental breakfast or continental breakfast alternative was offered to Member."

If the property has a lounge and it's open for breakfast, then the front desk is not required to mention it at check-in -- although it's good, normal customer service to inform the arriving Platinum Elite (and above) guest of the lounge location and lounge hours.

When there's no lounge or the lounge is closed, then it becomes somewhat ambiguous. The front desk is supposed to offer "daily continental breakfast in restaurant for Member +1 or Member can choose 750 Points per night of Stay." But it doesn't say that the compensation applies the second an arriving guest steps away from the front desk or that the guest should not bring up the subject. As others here have noted, I sometimes have to ask about breakfast when a front desk agent at check-in fails to mention it. In a few cases, I may have stepped away from the front desk before realizing the omission. Normally, the front desk then provides a quick apology, the breakfast hours, and breakfast vouchers (at hotels that use them).

If the front desk refuses to provide daily breakfast with an excuse that their restaurant is run by a third party or that their brand does not require it (counter to the Terms & Conditions), then I would not hesitate to politely demand breakfast and compensation. But that's never happened to me.

$100 U.S. guest compensation globally "if no continental breakfast or continental breakfast alternative was offered to Member" is in the "GUARANTEED LOUNGE ACCESS" table in the Terms & Conditions.