The CiviCRM code going to rc on 5 July (yours) has fixes in it relevant to T309349 so we want to get it out to get on top of that one.
Note the specific fix is that the currency as of now renders differently for (eg. ) CAD for someone with a preferred language of Canadian English vs US English. This means what is seen in the preview screen may differ from what is received. After the update the preview screen will be an accurate reflection
Note the standardised rendering in English United States is per below. The last option adds the iso code for USD only - where it would otherwise be deemed implicit by the php currency library because the language is en_US
| Currency | Template code | displays |
| CAD | {$amount} | $CA 50.00 |
| USD | {$amount} | $50.00 |
| CAD | {$amount} {$currency} | $CA 50.00 CAD |
| CAD | {$amount} {$currency} | $50.00 USD |
| CAD | {$amount} {if $currency ==='USD}{$currency}(/if} | $CA 50.00 |
| CAD | {$amount} {if $currency ==='USD}{$currency}(/if} | $50.00 USD |