As it seems there’s not only a technical incomprehention but also a language barrier, I will try to make it as easy as possible:
Blender is doing everything right, you don’t understand some things.
Image Aspect Ratio != Pixel Aspect Ratio != Broadcast Viewing Ratio
SAR * PAR = DAR
StorageAspectRatio * PixelAspectRatio = DisplayAspectRatio
PAL is an analog technology, and meant for analog devices.
SAR is always 5:4 which is 720x576 - that’s what PAL is
PAR for PAL 4:3 is 12:11
PAR for PAL 16:9 is 16:11
PAL 576i 4:3
Resolution = 720x576 -> SAR = 5:4
PAR = 12:11
Equivalent square-pixel resolution = 786x576 because 720*(12/11) = 786
A TV image shows the center 704 pixel, not the full 720 pixel, thus resulting in an TV resolution of the known 768x576 because 704*(12/11) = 768
PAL 576i 16:9
Resolutoin = 720x576 -> SAR = 5:4, nothing changes.
PAR = 16:11
Equivalent square-pixel resolution = 1048x576 because 720*(16/11) = 1048
And again, the TV image shows the center 704 pixel, resulting in 1024576 pixel image as 704(16/11) = 1024
This is what anamorphic is. Depending on what SAR and PAR you have, the receiver in your TV knows how to stretch the image and the 5:4 PAL stream is displayed as 4:3 or 16:9 image.
The TV signal is broadcast digitally and the 8 pixel strips on each side (720-2*8=704) are for nominal analogue blanking and are discarded. It’s an old technique and has to do with the horizontal blanking interval of a TV.
To be blunt, a todays kid will prolly neither know about it, nor need it as old tube TVs are pretty much a dying kind.
The only thing where this is still a topic is for DVD authoring as it contains either a PAL or NTSC stream.
HDTV 720i/p and 1080i/p are non anaglyphic and have a PAR of 1:1, so there are no problems and what you see is what you store and what you watch.
This should be a sticky, people should know this
I hope all the info is accurate, after all I might recall stuff wrong, and if so, freen or other watchful eyes surely can point out flaws in that short travel to gramps days of video