You can usually get an upgrade from one ship to another, provided the ship you are upgrading to costs more than the ship you currently have and the ship you are trying to upgrade to is currently on sale.
However, you can't upgrade to a limited ship this way. So you will not be able to purchase a CCU (upgrade) from your cutlass to a Connie Phoenix, Idris, Kraken, etc. Nor can you CCU to a subscriber sale (I think)
The November sale is indeed when they put most, but not all ships on sale. You will probably not be able to purchase a Kraken at the anniversary sale this year. The last few years when they had the Polaris and Pioneer up for concept sale at CitizenCon, the November anniversary sale did not contain them. I am also unsure if you will be able to purchase the Valkyrie as that is on sale this month.
So, you should be able to find your Sabre upgrade....
But also note, the sales are very short during the anniversary sale. Usually one day for each manufacturer over the first week, then a few more days (maybe as little as 1 day, might be as much as a week, I forget), you can buy all ships that were on sale that week. It's usually the last day.
One more thing for you to consider. The sabre is a fighter. It only does one thing. Fight. You will not be able to take delivery missions, recovery missions, etc. It doesn't have a single unit of cargo space, much less 1 SCU. It's a very limited ship. If this is going to be your only ship, you really need to consider that aspect. If you are good with it, that's fine and more power to you. The cutlass does combat fairly well, and while not a stealth ship and not a nimble fighter, it does have a lot of guns on it. It can also carry cargo which makes it a great all-rounder ship. Other good all-rounders that can fight AND trade are the freelancer base, and the Connie series (Andromeda).
If you still want a nimble fighter, but also want to carry cargo, consider the 325a, which I think has 2xS3 and 1xS4 weapon now, giving it a terrific punch, and with 2 SCU of cargo room, you will also be able to at least to recovery missions and maybe a little high risk/high reward trading. It also has the advantage of being cheap at $70 usd, which is the same price you are going to pay to upgrade from your cutlass to the sabre. If you want a dedicated fighter, the Gladius is a ton of fun and just 90 USD. By either getting the 325A or the Gladius, you get a fighter, plus you keep your cutlass, which is another great ship, so if you crash, or the game crashes and you want something to fly in while you wait for insurance, you will have it.
Small note: The 325a is under re-design and WILL change, but the weapons should be about the same. The main problem is the clipping issues being experience and just overall resources the ships takes up as it's one of the first ones designed.
Just want to be sure you have thought out all the pros and cons before you shell out money for a ship you will only be able to use one way. Again, if you do decide to go that way, that's fine. Play the way you want to.