My native language is English, but I have taught many international
students from countries that read right to left. My observation is
that in very simple examples such as your $A = B$, it makes no
difference at all, roughly for the reasons mentioned in Comments.
However for long displayed equations, it does seem to me that
these international students are more likely to look at the end
first. Sometimes this gives them valuable orientation as to
motivation. I often suggest that all students browse through
the whole equation to get an idea what is going on before
plunging into the details of justifying each equal sign,
inequality, or implication (from left to right).
On a related matter, many students in north Asia are taught
to deal with the denominator of a fraction before the numerator.
This has more to do with training and habits than with language
differences. However, there sometimes seems to be a real
advantage to looking at the denominator first. One example
of this is in probability problems with combinatorial
solutions: if both numerator and denominator count ordered
arrangements, this is often more quickly seen by looking
at the denominator first. Also, looking at denominators
first is sometimes an advantage in something as simple as
adding fractions that need a common denominator.
This is indeed more a psychology question than a mathematical
one, but there may be important implications for math
education. The relatively strong advantage of looking at
denominators first, may give added credence to my claim
that there is a (somewhat weaker) advantage in looking
at the end of an equation first.
For everyone, I think the lesson is to 'size up' a math
problem from several 'angles' before plunging in.