This is true. The CRT itself holds a small charge but at a huge voltage. So the current through you would be quite high but extremely short, and will not have time to do much damage.
Now, if you open up an old TV, what you REALLY need to watch out for are the big capacitors in the power supply. Those may be only the voltage of your power grid, but hold enough charge to power the whole TV for several milliseconds. On a 28”, that’s enough to kill you dead. Luckily the leads on those caps are not exposed unless you disassemble the TV (removing the PSU PCB).
Now, if you open up an old TV, what you REALLY need to watch out for are the big capacitors in the power supply. Those may be only the voltage of your power grid, but hold enough charge to power the whole TV for several milliseconds. On a 28”, that’s enough to kill you dead. Luckily the leads on those caps are not exposed unless you disassemble the TV (removing the PSU PCB).