A synthetic blend (why don't they ever call it mineral blend?) is purely a way for oil manufacturers and sellers to differentiate a product, build value in the consumer's mind, and raise the price for it but there are no standards for what a blend is. It could be 20% synthetic and 80% mineral or 80% synthetic and 20% mineral. In fact, after Castrol won the right to advertise a 30% blend of highly refined mineral oil base as a full synthetic, the line between what is mineral oil and synthetic was forever blurred. I'd never buy a synthetic blend - it's paying for the synthetic oil reputation and getting the benefits of a less expensive mineral oil based product. There's nothing wrong with the latter as a good dino oil meets or exceeds Honda's specifications across the entire product line from lawn mowers to sports cars but I'm darn sure not paying extra for it in a blend.

To the OP I'd run the oil out until it needs changing and pay for the oil you want next time and I'm sure you will check with the service writer beforehand to know what they are going to use. The blend that is in it now is fine and your engine will survive w/o no issue now or later.

I don't own a newer Fit so I can't check the manual but in the USA 0w20 recommendations often have more to do with meeting Corporate Average Fuel Economy than long engine life. Until the engine reaches operating temperature an engine with 0w20 has slightly less internal friction than the same engine using 5w20. For a manufacturer that needs to meet the CAFE in order to sell cars in the USA that slight increase in friction and fuel economy is very important.

My 2019 Mazda CX-5 manual thoughtfully lists the recommended oil viscosity for all of Central and North America. (Mexico, the Caribbean, USA and Canada). In the USA and Canada 0w30 is the recommendation but in every other country where CAFE standards don't apply it is 5w30.