I have enjoyed my MC452 for about two years now, compared it to the MC302 and thought it sounded better, just my opinion.
The MC452 is a current model. McIntosh will be announcing new products each month for the rest of 2017, so who knows, maybe an MC452 replacement is in the works. I think if you are patient, there are MC452's that come up for sale on Audiogon. When I bought mine, I was going to buy a new one, but someone had one he'd bought four months earlier, so I snagged that one for a good discount off of list.
I really really enjoy the sound of the MC452, driving a pair of Focal speakers with beryllium tweeters. I'm one of those nuts that buys that, sells this quite often, but no plans to sell the MC452!