I would think it is a question that can not be answered.
Like what came first the chicken or the egg ?
The first time you ride the bike it could get munched between some gears and be squished enough to never be a problem and make it's way to the oil filter.
The first time you ride the bike it could get stuck between some gears making gear changes impossible.
If it was my bike the first thing I would do is drop the oil again into a clean container so it can be reused then remove the clutch cover, there is a big chance you will find the bit just inside that cover, you may even be able to reuse the original gasket ??
If you can't see it select a gear & spin the rear wheel by hand always looking for the plastic bit.
A last resort would be to ride the bike around the block a few times then drop the oil again.
Your problem is the plastic is likely to float on the oil (you could test this with another spray bottle & some oil) even after being munched and if it moves and blocks a oil gallery a part on the motor could be starved of oil and that would be disaster.
I love short cuts but I think getting it out is the only real solution.
I make plastic for a living and I would take the risk of leaving it there if it was just a motor or just a manual gearbox but being a motor and manual gearbox in one makes all the difference, I would not risk it.
Some of the 19 rides in my shed
2014 V2, Snoopy
2009 Wee, Pumbaa the pig
WR450F, The Blue Postie Bike
YZ250N smoker with rego, Stinky.
Yamaha MT09 (FZ09), The Scud missile.
Club Lead not Club Med.
He with the most toys wins.
Out of my depth in a puddle.
Live life on the edge you will see more that way.
Ridding a motorcycle keeps things in balance.
At the end of each trail and at the end of each day history is made.