Need I change the device sda2 into sda5?

Why do you see a need to change sda2 into sda5?

For a correct understanding of device naming you have to know some details of partitioning:
The first partitioning schemes could only work with a maximum of four partitions per disk, numbered 1 to 4 (those nowadays are usually called primary partitions).
To raise that limit, the concept of extended partitions was created. One of these possible four entries was used not as a partition, but for some kind of table of contents for more partitions. This extended partition information table then uses one of the number 1 to 4, and all the partitions whose information is stored there, then get numbered 5 and higher.

As far as I can see from your previous question documents, you had a hard disk partitioned with a primary partition sda1, and an entry for extended partitions. There was only one extended partition called sda5.

Now you have resized and reworked your partitions, with sda1 being the same primary partition as before (just shrunk), and instead of an external partition that contains only one partition (was sda5), now there is just a second primary partition sda2 as swap.

The system does not care much what the numbers of the partition are. So I do not see any advantage of re-restructuring your partition layout to get back an extended partition with the swap partition inside.

And the priority -1 does not matter either. If you have only one single swap area, its priority is irrelevant. Only if you have more than one swap file, the system uses the one with higher priority first.