Same thing happened to me. Michelin on all 4 corners for 2 years 7mm tread and one puncture and the tyre replaced by a Continental at Kwik Fit.
It made zero difference to the cars handling, braking, noise, driveability.
Like yourself I was a tad concerned for 5 minutes, but its not my car.
You will in all probability not notice any change at all.
6 months later and it was all Continentals on the car.
Its not my car…lol. Many many years ago, it would be a problem, but not with modern tyres and vehicles. The are all probably made in the same Chinese factory anyway, with different moulds an logo’s …lol..