The marking is sometimes very strange but wouldn´t it be possible that TI has a chinese company building the last few cheap NE555-DIP and they are no longer interested in the perfect quality? The dies of "these modern" TI-NE555 seem to be all the same. There was only one die shrink. Could be a chinese fake-company. Could be a cheap TI-outsourcing...
I don't think TI has anything to do with those parts. Buy the cheapest TI NE555 you can find from any reputable distributor and I'm pretty sure you will find the original TI die, not the Chinese ones.
In other words, they are random Chinese 555s with the TI logo stamped on them by fraudsters. Sometimes it isn't even TI logo but some shapeless blob vaguely resembling TI logo to make it harder to sue them for trademark infringement. Still, auction site vendors sell it as TI.
I´m not sure about this.
I have found these three generations of "chinese TI-NE555" only in packages marked TI NE555.
There have to be plenty parts with this die. After all they made at least three complete mask revisions.
Why should they mark their fake parts only as TI NE555? Over all the years and all the sub marketer? Why not doing some TDB0555? TDB0555 make more money sold on ebay.
With round about 100 decapped NE555-variants I have a significant experience...
BTW: Beside the "chinese TI-NE555" till now I found no recognizable fake.