There needs to be some clarification here to what's being said.
There are a number of factors that come into play in the discontinuation of a part with the biggest one being demand.
Let's remember that Toyota is in the business of making money, and so are Toyota's suppliers (Tier 1 companies on down). If they are not making money on the sale of a part (it's "movement") then Toyota discontinues it-- regardless of what vehicle it's for.
So an air intake hose (17881-66060 or 17881-66080) for example, has a much better chance of being available for a longer period of time than say the 22250-66050 MAF for the 1FZ because of the following criteria:
- Cost to manufacture: (molded rubber hose is imminently cheaper than an electro-mechanical sensor)
- Necessity to manufacture (10 year rule for OEMs)
- Demand (rubber deteriorates faster than electro-mechanical components)
- Manufacturing requirements of said parts (rubber vs. an integrated electro-mechanical sensor)
As such, there are plenty of rubber hoses sitting on shelves in North American parts depots while there are currently 0 MAF's in North American supply since I just bought the last three in stock.
That said, there are certain things to remember as well...
The 80 series was a "world" vehicle vs. a region-specific/market-specific vehicle. While it's manufacture was discontinued in 1997 for most markets, other markets continued to receive the 80 series in CKD form (Complete Knock Down Kit)-- basically a parts car assembled in a regional manufacturing facility with a certain % of parts locally procured. This was the case for the 80 series manufacture in Venezuela.
So, ostensibly the last year of manufacture for the 80 series was 2005 and the last year of manufacture for the 1FZ engine family was actually 2009 (FZJ7x iterations).
2009 was ten years ago.
We will see a rapid reduction in both 80 series parts and more specifically 1FZ engine series parts moving forward as the normal 10 year parts production requirement is now over for this engine.
Of course, the aftermarket can step-in and provide replacements that are generally manufactured for a fraction of the OEM part and are, unfortunately, also of much less quality. And this is for most things, not ALL things-- there has to be a market.