Now, hitting /
(forward slash) will move focus to the query field, but the cursor will be at the end of the query. Usually you want to type a new query, so having whatever is in the query field selected automatically would allow you to type over it at once, instead of needing an extra step to clear the field. With the query text automatically selected, if occasionally you would want to append to the existing query instead of replacing it, hitting right arrow will put the cursor at the end of the query.
See above.