As salesforce documentation mentions,
if:true and if:false will beDeprecated. The if:true and if:false directives are no longer recommended. They may be deprecated and removed in the future. Use lwc:if, lwc:elseif, and lwc:else instead.
the link is : https://developer.salesforce.com/docs/component-library/documentation/en/lwc/lwc.reference_directives
I don't recommend this because there is some limitation about lwc:if & lwc:else. For example.
<template>
<template if:true={testVariable}>
show true
</template>
<br/>
test show other information
<br/>
<template if:false={testVariable}>
show false
</template>
</template>
This is AS-IS demo in our system, after lwc:if release, how should I quickly replace? As salesforce suggestion, lwc:if replaces to if:true and lwc:else replace to if:false. but below code will occurs error because 'lwc:else' directive must be used immediately after an element with 'lwc:if' or 'lwc:elseif'.@Release Team
<template>
<template lwc:if={testVariable}>
show true
</template>
<br/>
test show other information
<br/>
<template lwc:else>
show false
</template>
</template>
Don't know if I misunderstand the meaning of may be removed in the future, My understanding about this is that they will be no used and other reference must be also replaced with lwc:if / lwc:else. If my understanding is incorrect, please let me know, thanks.