What is the "Sayonara" (under)meaning?

Question:

In my Japanese textbook it is written that 'Sayonara" is used only when there is no intention of meeting again and can be a rude way of saying "good bye". The Japanese guy I've just chatted to said "Let's talk again" and then "Sayonara". Does that mean he dost not intend to chat again or is it normal?

Answer:

sayonara = bye.

so, let's talk again , sayonara.
it meaning
" See you later " or " I want meet once more. good bye. "

In boy friend and girl , only sayonara, it is just bye.
In chat room , In this case, may meaning "see you later".

<Japanese>
Try to be friendly and try to use "Japanese word".
Just mis-communication.

May he want meet you .
(from japanese)