The reservations can be made 180 days in advance, but multi day tickets can be purchased at any time. Unless you are buying only a 1-day ticket, you can buy your tickets now and make reservations later. This is what I do.
In fact, the general rule is to buy tickets as soon as you know you want to go. Tickets right now typically won't expire until January of 2026, and even if they expire, you can still use the value of the tickets towards future tickets.
The prices will likely go up again later this year, including
Genie+ and park hopping. Buy them now if you know you are going! I always look at
Undercover Tourist, as they have consistently great prices.
We bought our tickets for this summer last September before the most recent price increase. This saved us hundreds of dollars on the actual tickets, saved us money on the park hopping add on, and saved us $5 per person per day on Genie+. In fact, the tickets per day are cheaper than the incredible summer ticket promotion Disney is running.
In summary, if buying multi-day tickets - buy now and make reservations later!