Are you referring to the entire season, or just the plunder pass? The plunder pass items always arrive in the store at a later date, but the entire season doesn't.
I'm not against the idea entirely, I have definitely put Sea of Thieves down for now as I'm playing quite a lot of other games, but it would be nice to get some things I simply don't have time for, or for circumstances with adults with busy lives, getting close to finishing the whole season, but then they're going on vacation with the family and won't have time for it and whatnot. I know I missed out on a cosmetic I was interested in getting in the regular season because I just simply didn't have time to reach the level it was at, but had gotten pretty close to it.
It would also be nice if for the last week of the season, they have double renown for the season for people who want to catch up.
All of these are not new ideas, a lot of other live service games already do this. I think the extra funds could help Rare out, but I'm wondering if some players may view it negatively. (Some people will pay vs. work for the 'prestige' of earning said cosmetics outright)