Toasting today may not be viewed by many as a religious gesture. Still, there are valid reasons why Christians do not share in toasting, which has a religious background and even now can be viewed as asking ‘heaven’ for a blessing, as if seeking aid from a superhuman force.—Exodus 23:2.
http://wol.jw.org/en/wol/d/r1/lp-e/2007128#h=1:0-11:881
That is the most recent thing on toasting I can find (Stay in Gods Love is newer, but simply refers to this article without adding info)
The article I quote from is an excellent example of how to contradict yourself. Basically there are no real arguments but 'Watchtower says so'. Which may be why some have taken that as 'without Bible base objections, it's a matter of conscience'.