Think about yourself as a reader, do you prefer to read out loud most of the time or is it more efficient and easier to comprehend when reading silently? Just like adults, as most children become older, the reading process moves from a verbal activity to more of an "in the head" process. Yet there are always some older students and adults alike who need to read aloud to hear themselves as it helps with their comprehension.
That said, during Daily 5 with older students, do we have them switch their choice from Read to Self into Read to Someone during one rotation? The typical answer is no. As Kelly Gallagher, author of Readicide says, we want our students to get into the "reading flow." You may know that place, where you have the time to fall into a book so much that you loose track of everything but the book you are engaged with. If we make a habit of allowing students to switch choices during a rotation, they loose that sense of flow.
Of course, because we are dealing with humans, we also know there is never one complete, definitive rule that applies to all students. You may find that you have a student or two who needs to have some of their reading time spent reading aloud and then the other time spent reading to themselves. That is the greatest part of being a teacher, to figure out what is best for each individual student in our care and then have the power to make it happen.
When we find our students want to 'switch' choices in the middle of a round, there are a few things we consider: Do they have a Good Fit Book that is the correct readability and one they can truly engage with? Do they want to switch because they lack enough stamina to stick with one choice the whole time? If either of those is the issue, supporting the child individually is the plan of action. Spending time to learn about their reading interests and helping match them to a book is a wonderful investment. Often we will even 'get the book started' with a reader, reading aloud to them the first pages or chapter so we scaffold them as they make sense of the characters, setting etc. When we see many students wanting to switch and we believe it is due to lack of stamina, we either pull the whole class back for a review on stamina and work a bit on building stamina again, or if it is just a few students, we will review the I-chart and redo the 10 Steps of Independence lesson with just that group.