Where exactly did you read that? It is certainly not true for the version I have (v3.14.0). The only major difference in --meta mode is that --careful is not supported. See the input options below.

Input data:
  --12 <filename>             file with interlaced forward and reverse paired-end reads
  -1 <filename>               file with forward paired-end reads
  -2 <filename>               file with reverse paired-end reads
  -s <filename>               file with unpaired reads
  --merged <filename>         file with merged forward and reverse paired-end reads
  --pe-12 <#> <filename>      file with interlaced reads for paired-end library number <#>.
                              Older deprecated syntax is -pe<#>-12 <filename>
  --pe-1 <#> <filename>       file with forward reads for paired-end library number <#>.
                              Older deprecated syntax is -pe<#>-1 <filename>
  --pe-2 <#> <filename>       file with reverse reads for paired-end library number <#>.
                              Older deprecated syntax is -pe<#>-2 <filename>
  --pe-s <#> <filename>       file with unpaired reads for paired-end library number <#>.
                              Older deprecated syntax is -pe<#>-s <filename>
  --pe-m <#> <filename>       file with merged reads for paired-end library number <#>.
                              Older deprecated syntax is -pe<#>-m <filename>
  --pe-or <#> <or>            orientation of reads for paired-end library number <#>
                              (<or> = fr, rf, ff).
                              Older deprecated syntax is -pe<#>-<or>
  --s <#> <filename>          file with unpaired reads for single reads library number <#>.
                              Older deprecated syntax is --s<#> <filename>
  --pacbio <filename>         file with PacBio reads
  --nanopore <filename>       file with Nanopore reads
  --tslr <filename>           file with TSLR-contigs